Update kiwisolver to 1.2.0

11 files changed, 768 insertions, 1786 deletions

diff --git a/contrib/python/kiwisolver/py3/py/constraint.cpp b/contrib/python/kiwisolver/py3/py/constraint.cpp
index 2fbdd0aeb83..e5b516919e8 100644
--- a/contrib/python/kiwisolver/py3/py/constraint.cpp
+++ b/contrib/python/kiwisolver/py3/py/constraint.cpp
@@ -1,299 +1,201 @@
 /*-----------------------------------------------------------------------------
-| Copyright (c) 2013-2017, Nucleic Development Team.
+| Copyright (c) 2013-2019, Nucleic Development Team.
 |
 | Distributed under the terms of the Modified BSD License.
 |
-| The full license is in the file COPYING.txt, distributed with this software.
+| The full license is in the file LICENSE, distributed with this software.
 |----------------------------------------------------------------------------*/
 #include <algorithm>
 #include <sstream>
-#include <Python.h>
+#include <cppy/cppy.h>
 #include <kiwi/kiwi.h>
-#include "pythonhelpers.h"
 #include "types.h"
 #include "util.h"
 
+namespace kiwisolver
+{
 
-using namespace PythonHelpers;
-
+namespace
+{
 
-static PyObject*
-Constraint_new( PyTypeObject* type, PyObject* args, PyObject* kwargs )
+PyObject *
+Constraint_new(PyTypeObject *type, PyObject *args, PyObject *kwargs)
 {
-    static const char *kwlist[] = { "expression", "op", "strength", 0 };
-    PyObject* pyexpr;
-    PyObject* pyop;
-    PyObject* pystrength = 0;
-    if( !PyArg_ParseTupleAndKeywords(
-        args, kwargs, "OO|O:__new__", const_cast<char**>( kwlist ),
-        &pyexpr, &pyop, &pystrength ) )
+    static const char *kwlist[] = {"expression", "op", "strength", 0};
+    PyObject *pyexpr;
+    PyObject *pyop;
+    PyObject *pystrength = 0;
+    if (!PyArg_ParseTupleAndKeywords(
+            args, kwargs, "OO|O:__new__", const_cast<char **>(kwlist),
+            &pyexpr, &pyop, &pystrength))
         return 0;
-    if( !Expression::TypeCheck( pyexpr ) )
-        return py_expected_type_fail( pyexpr, "Expression" );
+    if (!Expression::TypeCheck(pyexpr))
+        return cppy::type_error(pyexpr, "Expression");
     kiwi::RelationalOperator op;
-    if( !convert_to_relational_op( pyop, op ) )
+    if (!convert_to_relational_op(pyop, op))
         return 0;
     double strength = kiwi::strength::required;
-    if( pystrength && !convert_to_strength( pystrength, strength ) )
+    if (pystrength && !convert_to_strength(pystrength, strength))
         return 0;
-    PyObjectPtr pycn( PyType_GenericNew( type, args, kwargs ) );
-    if( !pycn )
+    cppy::ptr pycn(PyType_GenericNew(type, args, kwargs));
+    if (!pycn)
         return 0;
-    Constraint* cn = reinterpret_cast<Constraint*>( pycn.get() );
-    cn->expression = reduce_expression( pyexpr );
-    if( !cn->expression )
+    Constraint *cn = reinterpret_cast<Constraint *>(pycn.get());
+    cn->expression = reduce_expression(pyexpr);
+    if (!cn->expression)
         return 0;
-    kiwi::Expression expr( convert_to_kiwi_expression( cn->expression ) );
-    new( &cn->constraint ) kiwi::Constraint( expr, op, strength );
+    kiwi::Expression expr(convert_to_kiwi_expression(cn->expression));
+    new (&cn->constraint) kiwi::Constraint(expr, op, strength);
     return pycn.release();
 }
 
-
-static void
-Constraint_clear( Constraint* self )
+void Constraint_clear(Constraint *self)
 {
-    Py_CLEAR( self->expression );
+    Py_CLEAR(self->expression);
 }
 
-
-static int
-Constraint_traverse( Constraint* self, visitproc visit, void* arg )
+int Constraint_traverse(Constraint *self, visitproc visit, void *arg)
 {
-    Py_VISIT( self->expression );
+    Py_VISIT(self->expression);
     return 0;
 }
 
-
-static void
-Constraint_dealloc( Constraint* self )
+void Constraint_dealloc(Constraint *self)
 {
-    PyObject_GC_UnTrack( self );
-    Constraint_clear( self );
+    PyObject_GC_UnTrack(self);
+    Constraint_clear(self);
     self->constraint.~Constraint();
-    Py_TYPE( self )->tp_free( pyobject_cast( self ) );
+    Py_TYPE(self)->tp_free(pyobject_cast(self));
 }
 
-
-static PyObject*
-Constraint_repr( Constraint* self )
+PyObject *
+Constraint_repr(Constraint *self)
 {
     std::stringstream stream;
-    Expression* expr = reinterpret_cast<Expression*>( self->expression );
-    Py_ssize_t size = PyTuple_GET_SIZE( expr->terms );
-    for( Py_ssize_t i = 0; i < size; ++i )
+    Expression *expr = reinterpret_cast<Expression *>(self->expression);
+    Py_ssize_t size = PyTuple_GET_SIZE(expr->terms);
+    for (Py_ssize_t i = 0; i < size; ++i)
     {
-        PyObject* item = PyTuple_GET_ITEM( expr->terms, i );
-        Term* term = reinterpret_cast<Term*>( item );
+        PyObject *item = PyTuple_GET_ITEM(expr->terms, i);
+        Term *term = reinterpret_cast<Term *>(item);
         stream << term->coefficient << " * ";
-        stream << reinterpret_cast<Variable*>( term->variable )->variable.name();
+        stream << reinterpret_cast<Variable *>(term->variable)->variable.name();
         stream << " + ";
     }
     stream << expr->constant;
-    switch( self->constraint.op() )
+    switch (self->constraint.op())
     {
-        case kiwi::OP_EQ:
-            stream << " == 0";
-            break;
-        case kiwi::OP_LE:
-            stream << " <= 0";
-            break;
-        case kiwi::OP_GE:
-            stream << " >= 0";
-            break;
+    case kiwi::OP_EQ:
+        stream << " == 0";
+        break;
+    case kiwi::OP_LE:
+        stream << " <= 0";
+        break;
+    case kiwi::OP_GE:
+        stream << " >= 0";
+        break;
     }
     stream << " | strength = " << self->constraint.strength();
-    return FROM_STRING( stream.str().c_str() );
+    return PyUnicode_FromString(stream.str().c_str());
 }
 
-
-static PyObject*
-Constraint_expression( Constraint* self )
+PyObject *
+Constraint_expression(Constraint *self)
 {
-    return newref( self->expression );
+    return cppy::incref(self->expression);
 }
 
-
-static PyObject*
-Constraint_op( Constraint* self )
+PyObject *
+Constraint_op(Constraint *self)
 {
-    PyObject* res = 0;
-    switch( self->constraint.op() )
+    PyObject *res = 0;
+    switch (self->constraint.op())
     {
-        case kiwi::OP_EQ:
-            res = FROM_STRING( "==" );
-            break;
-        case kiwi::OP_LE:
-            res = FROM_STRING( "<=" );
-            break;
-        case kiwi::OP_GE:
-            res = FROM_STRING( ">=" );
-            break;
+    case kiwi::OP_EQ:
+        res = PyUnicode_FromString("==");
+        break;
+    case kiwi::OP_LE:
+        res = PyUnicode_FromString("<=");
+        break;
+    case kiwi::OP_GE:
+        res = PyUnicode_FromString(">=");
+        break;
     }
     return res;
 }
 
-
-static PyObject*
-Constraint_strength( Constraint* self )
+PyObject *
+Constraint_strength(Constraint *self)
 {
-    return PyFloat_FromDouble( self->constraint.strength() );
+    return PyFloat_FromDouble(self->constraint.strength());
 }
 
-
-static PyObject*
-Constraint_or( PyObject* pyoldcn, PyObject* value )
+PyObject *
+Constraint_or(PyObject *pyoldcn, PyObject *value)
 {
-    if( !Constraint::TypeCheck( pyoldcn ) )
-        std::swap( pyoldcn, value );
+    if (!Constraint::TypeCheck(pyoldcn))
+        std::swap(pyoldcn, value);
     double strength;
-    if( !convert_to_strength( value, strength ) )
+    if (!convert_to_strength(value, strength))
         return 0;
-    PyObject* pynewcn = PyType_GenericNew( &Constraint_Type, 0, 0 );
-    if( !pynewcn )
+    PyObject *pynewcn = PyType_GenericNew(Constraint::TypeObject, 0, 0);
+    if (!pynewcn)
         return 0;
-    Constraint* oldcn = reinterpret_cast<Constraint*>( pyoldcn );
-    Constraint* newcn = reinterpret_cast<Constraint*>( pynewcn );
-    newcn->expression = newref( oldcn->expression );
-    new( &newcn->constraint ) kiwi::Constraint( oldcn->constraint, strength );
+    Constraint *oldcn = reinterpret_cast<Constraint *>(pyoldcn);
+    Constraint *newcn = reinterpret_cast<Constraint *>(pynewcn);
+    newcn->expression = cppy::incref(oldcn->expression);
+    new (&newcn->constraint) kiwi::Constraint(oldcn->constraint, strength);
     return pynewcn;
 }
 
-
 static PyMethodDef
-Constraint_methods[] = {
-    { "expression", ( PyCFunction )Constraint_expression, METH_NOARGS,
-      "Get the expression object for the constraint." },
-    { "op", ( PyCFunction )Constraint_op, METH_NOARGS,
-      "Get the relational operator for the constraint." },
-    { "strength", ( PyCFunction )Constraint_strength, METH_NOARGS,
-      "Get the strength for the constraint." },
-    { 0 } // sentinel
+    Constraint_methods[] = {
+        {"expression", (PyCFunction)Constraint_expression, METH_NOARGS,
+         "Get the expression object for the constraint."},
+        {"op", (PyCFunction)Constraint_op, METH_NOARGS,
+         "Get the relational operator for the constraint."},
+        {"strength", (PyCFunction)Constraint_strength, METH_NOARGS,
+         "Get the strength for the constraint."},
+        {0} // sentinel
 };
 
-
-static PyNumberMethods
-Constraint_as_number = {
-    0,                          /* nb_add */
-    0,                          /* nb_subtract */
-    0,                          /* nb_multiply */
-#if PY_MAJOR_VERSION < 3
-    0,                          /* nb_divide */
-#endif
-    0,                          /* nb_remainder */
-    0,                          /* nb_divmod */
-    0,                          /* nb_power */
-    0,                          /* nb_negative */
-    0,                          /* nb_positive */
-    0,                          /* nb_absolute */
-#if PY_MAJOR_VERSION >= 3
-    0,                          /* nb_bool */
-#else
-    0,                          /* nb_nonzero */
-#endif
-    0,                          /* nb_invert */
-    0,                          /* nb_lshift */
-    0,                          /* nb_rshift */
-    0,                          /* nb_and */
-    0,                          /* nb_xor */
-    (binaryfunc)Constraint_or,  /* nb_or */
-#if PY_MAJOR_VERSION < 3
-    0,                          /* nb_coerce */
-#endif
-    0,                          /* nb_int */
-    0,                          /* nb_long */
-    0,                          /* nb_float */
-#if PY_MAJOR_VERSION < 3
-    0,                          /* nb_oct */
-    0,                          /* nb_hex */
-#endif
-    0,                          /* nb_inplace_add */
-    0,                          /* nb_inplace_subtract */
-    0,                          /* nb_inplace_multiply */
-#if PY_MAJOR_VERSION < 3
-    0,                          /* nb_inplace_divide */
-#endif
-    0,                          /* nb_inplace_remainder */
-    0,                          /* nb_inplace_power */
-    0,                          /* nb_inplace_lshift */
-    0,                          /* nb_inplace_rshift */
-    0,                          /* nb_inplace_and */
-    0,                          /* nb_inplace_xor */
-    0,                          /* nb_inplace_or */
-    (binaryfunc)0,              /* nb_floor_divide */
-    (binaryfunc)0,              /* nb_true_divide */
-    0,                          /* nb_inplace_floor_divide */
-    0,                          /* nb_inplace_true_divide */
-#if PY_VERSION_HEX >= 0x02050000
-    (unaryfunc)0,               /* nb_index */
-#endif
-#if PY_VERSION_HEX >= 0x03050000
-    (binaryfunc)0,              /* nb_matrix_multiply */
-    (binaryfunc)0,              /* nb_inplace_matrix_multiply */
-#endif
+static PyType_Slot Constraint_Type_slots[] = {
+    {Py_tp_dealloc, void_cast(Constraint_dealloc)},   /* tp_dealloc */
+    {Py_tp_traverse, void_cast(Constraint_traverse)}, /* tp_traverse */
+    {Py_tp_clear, void_cast(Constraint_clear)},       /* tp_clear */
+    {Py_tp_repr, void_cast(Constraint_repr)},         /* tp_repr */
+    {Py_tp_methods, void_cast(Constraint_methods)},   /* tp_methods */
+    {Py_tp_new, void_cast(Constraint_new)},           /* tp_new */
+    {Py_tp_alloc, void_cast(PyType_GenericAlloc)},    /* tp_alloc */
+    {Py_tp_free, void_cast(PyObject_GC_Del)},         /* tp_free */
+    {Py_nb_or, void_cast(Constraint_or)},             /* nb_or */
+    {0, 0},
 };
 
+} // namespace
 
-PyTypeObject Constraint_Type = {
-    PyVarObject_HEAD_INIT( &PyType_Type, 0 )
-    "kiwisolver.Constraint",                /* tp_name */
-    sizeof( Constraint ),                   /* tp_basicsize */
-    0,                                      /* tp_itemsize */
-    (destructor)Constraint_dealloc,         /* tp_dealloc */
-    (printfunc)0,                           /* tp_print */
-    (getattrfunc)0,                         /* tp_getattr */
-    (setattrfunc)0,                         /* tp_setattr */
-#if PY_VERSION_HEX >= 0x03050000
-    ( PyAsyncMethods* )0,                   /* tp_as_async */
-#elif PY_VERSION_HEX >= 0x03000000
-    ( void* ) 0,                            /* tp_reserved */
-#else
-    ( cmpfunc )0,                           /* tp_compare */
-#endif
-    (reprfunc)Constraint_repr,              /* tp_repr */
-    (PyNumberMethods*)&Constraint_as_number,/* tp_as_number */
-    (PySequenceMethods*)0,                  /* tp_as_sequence */
-    (PyMappingMethods*)0,                   /* tp_as_mapping */
-    (hashfunc)0,                            /* tp_hash */
-    (ternaryfunc)0,                         /* tp_call */
-    (reprfunc)0,                            /* tp_str */
-    (getattrofunc)0,                        /* tp_getattro */
-    (setattrofunc)0,                        /* tp_setattro */
-    (PyBufferProcs*)0,                      /* tp_as_buffer */
-#if PY_MAJOR_VERSION >= 3
-    Py_TPFLAGS_DEFAULT|Py_TPFLAGS_HAVE_GC|Py_TPFLAGS_BASETYPE, /* tp_flags */
-#else
-    Py_TPFLAGS_DEFAULT|Py_TPFLAGS_HAVE_GC|Py_TPFLAGS_BASETYPE|Py_TPFLAGS_CHECKTYPES, /* tp_flags */
-#endif
-    0,                                      /* Documentation string */
-    (traverseproc)Constraint_traverse,      /* tp_traverse */
-    (inquiry)Constraint_clear,              /* tp_clear */
-    (richcmpfunc)0,                         /* tp_richcompare */
-    0,                                      /* tp_weaklistoffset */
-    (getiterfunc)0,                         /* tp_iter */
-    (iternextfunc)0,                        /* tp_iternext */
-    (struct PyMethodDef*)Constraint_methods,/* tp_methods */
-    (struct PyMemberDef*)0,                 /* tp_members */
-    0,                                      /* tp_getset */
-    0,                                      /* tp_base */
-    0,                                      /* tp_dict */
-    (descrgetfunc)0,                        /* tp_descr_get */
-    (descrsetfunc)0,                        /* tp_descr_set */
-    0,                                      /* tp_dictoffset */
-    (initproc)0,                            /* tp_init */
-    (allocfunc)PyType_GenericAlloc,         /* tp_alloc */
-    (newfunc)Constraint_new,                /* tp_new */
-    (freefunc)PyObject_GC_Del,              /* tp_free */
-    (inquiry)0,                             /* tp_is_gc */
-    0,                                      /* tp_bases */
-    0,                                      /* tp_mro */
-    0,                                      /* tp_cache */
-    0,                                      /* tp_subclasses */
-    0,                                      /* tp_weaklist */
-    (destructor)0                           /* tp_del */
-};
+// Initialize static variables (otherwise the compiler eliminates them)
+PyTypeObject *Constraint::TypeObject = NULL;
 
+PyType_Spec Constraint::TypeObject_Spec = {
+    "kiwisolver.Constraint", /* tp_name */
+    sizeof(Constraint),      /* tp_basicsize */
+    0,                       /* tp_itemsize */
+    Py_TPFLAGS_DEFAULT |
+        Py_TPFLAGS_HAVE_GC |
+        Py_TPFLAGS_BASETYPE, /* tp_flags */
+    Constraint_Type_slots    /* slots */
+};
 
-int import_constraint()
+bool Constraint::Ready()
 {
-    return PyType_Ready( &Constraint_Type );
+    // The reference will be handled by the module to which we will add the type
+    TypeObject = pytype_cast(PyType_FromSpec(&TypeObject_Spec));
+    if (!TypeObject)
+    {
+        return false;
+    }
+    return true;
 }
+
+} // namespace kiwisolver
diff --git a/contrib/python/kiwisolver/py3/py/expression.cpp b/contrib/python/kiwisolver/py3/py/expression.cpp
index 5cd34e4c120..235e463f124 100644
--- a/contrib/python/kiwisolver/py3/py/expression.cpp
+++ b/contrib/python/kiwisolver/py3/py/expression.cpp
@@ -1,22 +1,24 @@
 /*-----------------------------------------------------------------------------
-| Copyright (c) 2013-2017, Nucleic Development Team.
+| Copyright (c) 2013-2019, Nucleic Development Team.
 |
 | Distributed under the terms of the Modified BSD License.
 |
-| The full license is in the file COPYING.txt, distributed with this software.
+| The full license is in the file LICENSE, distributed with this software.
 |----------------------------------------------------------------------------*/
 #include <sstream>
-#include <Python.h>
-#include "pythonhelpers.h"
+#include <cppy/cppy.h>
 #include "symbolics.h"
 #include "types.h"
 #include "util.h"
 
 
-using namespace PythonHelpers;
+namespace kiwisolver
+{
 
+namespace
+{
 
-static PyObject*
+PyObject*
 Expression_new( PyTypeObject* type, PyObject* args, PyObject* kwargs )
 {
     static const char *kwlist[] = { "terms", "constant", 0 };
@@ -26,7 +28,7 @@ Expression_new( PyTypeObject* type, PyObject* args, PyObject* kwargs )
         args, kwargs, "O|O:__new__", const_cast<char**>( kwlist ),
         &pyterms, &pyconstant ) )
         return 0;
-    PyObjectPtr terms( PySequence_Tuple( pyterms ) );
+    cppy::ptr terms( PySequence_Tuple( pyterms ) );
     if( !terms )
         return 0;
     Py_ssize_t end = PyTuple_GET_SIZE( terms.get() );
@@ -34,7 +36,7 @@ Expression_new( PyTypeObject* type, PyObject* args, PyObject* kwargs )
     {
         PyObject* item = PyTuple_GET_ITEM( terms.get(), i );
         if( !Term::TypeCheck( item ) )
-            return py_expected_type_fail( item, "Term" );
+            return cppy::type_error( item, "Term" );
     }
     double constant = 0.0;
     if( pyconstant && !convert_to_double( pyconstant, constant ) )
@@ -49,14 +51,14 @@ Expression_new( PyTypeObject* type, PyObject* args, PyObject* kwargs )
 }
 
 
-static void
+void
 Expression_clear( Expression* self )
 {
     Py_CLEAR( self->terms );
 }
 
 
-static int
+int
 Expression_traverse( Expression* self, visitproc visit, void* arg )
 {
     Py_VISIT( self->terms );
@@ -64,7 +66,7 @@ Expression_traverse( Expression* self, visitproc visit, void* arg )
 }
 
 
-static void
+void
 Expression_dealloc( Expression* self )
 {
     PyObject_GC_UnTrack( self );
@@ -73,7 +75,7 @@ Expression_dealloc( Expression* self )
 }
 
 
-static PyObject*
+PyObject*
 Expression_repr( Expression* self )
 {
     std::stringstream stream;
@@ -87,25 +89,25 @@ Expression_repr( Expression* self )
         stream << " + ";
     }
     stream << self->constant;
-    return FROM_STRING( stream.str().c_str() );
+    return PyUnicode_FromString( stream.str().c_str() );
 }
 
 
-static PyObject*
+PyObject*
 Expression_terms( Expression* self )
 {
-    return newref( self->terms );
+    return cppy::incref( self->terms );
 }
 
 
-static PyObject*
+PyObject*
 Expression_constant( Expression* self )
 {
     return PyFloat_FromDouble( self->constant );
 }
 
 
-static PyObject*
+PyObject*
 Expression_value( Expression* self )
 {
     double result = self->constant;
@@ -121,42 +123,42 @@ Expression_value( Expression* self )
 }
 
 
-static PyObject*
+PyObject*
 Expression_add( PyObject* first, PyObject* second )
 {
     return BinaryInvoke<BinaryAdd, Expression>()( first, second );
 }
 
 
-static PyObject*
+PyObject*
 Expression_sub( PyObject* first, PyObject* second )
 {
     return BinaryInvoke<BinarySub, Expression>()( first, second );
 }
 
 
-static PyObject*
+PyObject*
 Expression_mul( PyObject* first, PyObject* second )
 {
     return BinaryInvoke<BinaryMul, Expression>()( first, second );
 }
 
 
-static PyObject*
+PyObject*
 Expression_div( PyObject* first, PyObject* second )
 {
     return BinaryInvoke<BinaryDiv, Expression>()( first, second );
 }
 
 
-static PyObject*
+PyObject*
 Expression_neg( PyObject* value )
 {
     return UnaryInvoke<UnaryNeg, Expression>()( value );
 }
 
 
-static PyObject*
+PyObject*
 Expression_richcmp( PyObject* first, PyObject* second, int op )
 {
     switch( op )
@@ -194,133 +196,52 @@ Expression_methods[] = {
 };
 
 
-static PyNumberMethods
-Expression_as_number = {
-    (binaryfunc)Expression_add, /* nb_add */
-    (binaryfunc)Expression_sub, /* nb_subtract */
-    (binaryfunc)Expression_mul, /* nb_multiply */
-#if PY_MAJOR_VERSION < 3
-    (binaryfunc)Expression_div, /* nb_divide */
-#endif
-    0,                          /* nb_remainder */
-    0,                          /* nb_divmod */
-    0,                          /* nb_power */
-    (unaryfunc)Expression_neg,  /* nb_negative */
-    0,                          /* nb_positive */
-    0,                          /* nb_absolute */
-#if PY_MAJOR_VERSION >= 3
-    0,                          /* nb_bool */
-#else
-    0,                          /* nb_nonzero */
-#endif
-    0,                          /* nb_invert */
-    0,                          /* nb_lshift */
-    0,                          /* nb_rshift */
-    0,                          /* nb_and */
-    0,                          /* nb_xor */
-    (binaryfunc)0,              /* nb_or */
-#if PY_MAJOR_VERSION < 3
-    0,                          /* nb_coerce */
-#endif
-    0,                          /* nb_int */
-#if PY_MAJOR_VERSION >= 3
-    (void *)0,                  /* nb_reserved */
-#else
-    0,                          /* nb_long */
-#endif
-    0,                          /* nb_float */
-#if PY_MAJOR_VERSION < 3
-    0,                          /* nb_oct */
-    0,                          /* nb_hex */
-#endif
-    0,                          /* nb_inplace_add */
-    0,                          /* nb_inplace_subtract */
-    0,                          /* nb_inplace_multiply */
-#if PY_MAJOR_VERSION < 3
-    0,                          /* nb_inplace_divide */
-#endif
-    0,                          /* nb_inplace_remainder */
-    0,                          /* nb_inplace_power */
-    0,                          /* nb_inplace_lshift */
-    0,                          /* nb_inplace_rshift */
-    0,                          /* nb_inplace_and */
-    0,                          /* nb_inplace_xor */
-    0,                          /* nb_inplace_or */
-    (binaryfunc)0,              /* nb_floor_divide */
-    (binaryfunc)Expression_div, /* nb_true_divide */
-    0,                          /* nb_inplace_floor_divide */
-    0,                          /* nb_inplace_true_divide */
-#if PY_VERSION_HEX >= 0x02050000
-    (unaryfunc)0,               /* nb_index */
-#endif
-#if PY_VERSION_HEX >= 0x03050000
-    (binaryfunc)0,              /* nb_matrix_multiply */
-    (binaryfunc)0,              /* nb_inplace_matrix_multiply */
-#endif
+static PyType_Slot Expression_Type_slots[] = {
+    { Py_tp_dealloc, void_cast( Expression_dealloc ) },      /* tp_dealloc */
+    { Py_tp_traverse, void_cast( Expression_traverse ) },    /* tp_traverse */
+    { Py_tp_clear, void_cast( Expression_clear ) },          /* tp_clear */
+    { Py_tp_repr, void_cast( Expression_repr ) },            /* tp_repr */
+    { Py_tp_richcompare, void_cast( Expression_richcmp ) },  /* tp_richcompare */
+    { Py_tp_methods, void_cast( Expression_methods ) },      /* tp_methods */
+    { Py_tp_new, void_cast( Expression_new ) },              /* tp_new */
+    { Py_tp_alloc, void_cast( PyType_GenericAlloc ) },       /* tp_alloc */
+    { Py_tp_free, void_cast( PyObject_GC_Del ) },            /* tp_free */
+    { Py_nb_add, void_cast( Expression_add ) },              /* nb_add */
+    { Py_nb_subtract, void_cast( Expression_sub ) },         /* nb_sub */
+    { Py_nb_multiply, void_cast( Expression_mul ) },         /* nb_mul */
+    { Py_nb_negative, void_cast( Expression_neg ) },         /* nb_neg */
+    { Py_nb_true_divide, void_cast( Expression_div ) },      /* nb_div */
+    { 0, 0 },
 };
 
 
-PyTypeObject Expression_Type = {
-    PyVarObject_HEAD_INIT( &PyType_Type, 0 )
-    "kiwisolver.Expression",                /* tp_name */
-    sizeof( Expression ),                   /* tp_basicsize */
-    0,                                      /* tp_itemsize */
-    (destructor)Expression_dealloc,         /* tp_dealloc */
-    (printfunc)0,                           /* tp_print */
-    (getattrfunc)0,                         /* tp_getattr */
-    (setattrfunc)0,                         /* tp_setattr */
-#if PY_VERSION_HEX >= 0x03050000
-    ( PyAsyncMethods* )0,                   /* tp_as_async */
-#elif PY_VERSION_HEX >= 0x03000000
-    ( void* ) 0,                            /* tp_reserved */
-#else
-    ( cmpfunc )0,                           /* tp_compare */
-#endif
-    (reprfunc)Expression_repr,              /* tp_repr */
-    (PyNumberMethods*)&Expression_as_number,/* tp_as_number */
-    (PySequenceMethods*)0,                  /* tp_as_sequence */
-    (PyMappingMethods*)0,                   /* tp_as_mapping */
-    (hashfunc)0,                            /* tp_hash */
-    (ternaryfunc)0,                         /* tp_call */
-    (reprfunc)0,                            /* tp_str */
-    (getattrofunc)0,                        /* tp_getattro */
-    (setattrofunc)0,                        /* tp_setattro */
-    (PyBufferProcs*)0,                      /* tp_as_buffer */
-#if PY_MAJOR_VERSION >= 3
-    Py_TPFLAGS_DEFAULT|Py_TPFLAGS_HAVE_GC|Py_TPFLAGS_BASETYPE,
-#else
-    Py_TPFLAGS_DEFAULT|Py_TPFLAGS_HAVE_GC|Py_TPFLAGS_BASETYPE|Py_TPFLAGS_CHECKTYPES, /* tp_flags */
-#endif
-    0,                                      /* Documentation string */
-    (traverseproc)Expression_traverse,      /* tp_traverse */
-    (inquiry)Expression_clear,              /* tp_clear */
-    (richcmpfunc)Expression_richcmp,        /* tp_richcompare */
-    0,                                      /* tp_weaklistoffset */
-    (getiterfunc)0,                         /* tp_iter */
-    (iternextfunc)0,                        /* tp_iternext */
-    (struct PyMethodDef*)Expression_methods,/* tp_methods */
-    (struct PyMemberDef*)0,                 /* tp_members */
-    0,                                      /* tp_getset */
-    0,                                      /* tp_base */
-    0,                                      /* tp_dict */
-    (descrgetfunc)0,                        /* tp_descr_get */
-    (descrsetfunc)0,                        /* tp_descr_set */
-    0,                                      /* tp_dictoffset */
-    (initproc)0,                            /* tp_init */
-    (allocfunc)PyType_GenericAlloc,         /* tp_alloc */
-    (newfunc)Expression_new,                /* tp_new */
-    (freefunc)PyObject_GC_Del,              /* tp_free */
-    (inquiry)0,                             /* tp_is_gc */
-    0,                                      /* tp_bases */
-    0,                                      /* tp_mro */
-    0,                                      /* tp_cache */
-    0,                                      /* tp_subclasses */
-    0,                                      /* tp_weaklist */
-    (destructor)0                           /* tp_del */
+} // namespace
+
+
+// Initialize static variables (otherwise the compiler eliminates them)
+PyTypeObject* Expression::TypeObject = NULL;
+
+
+PyType_Spec Expression::TypeObject_Spec = {
+	"kiwisolver.Expression",             /* tp_name */
+	sizeof( Expression ),                /* tp_basicsize */
+	0,                                   /* tp_itemsize */
+	Py_TPFLAGS_DEFAULT|
+    Py_TPFLAGS_HAVE_GC|
+    Py_TPFLAGS_BASETYPE,                 /* tp_flags */
+    Expression_Type_slots                /* slots */
 };
 
 
-int import_expression()
+bool Expression::Ready()
 {
-    return PyType_Ready( &Expression_Type );
+    // The reference will be handled by the module to which we will add the type
+	TypeObject = pytype_cast( PyType_FromSpec( &TypeObject_Spec ) );
+    if( !TypeObject )
+    {
+        return false;
+    }
+    return true;
 }
+
+}  // namesapce kiwisolver
diff --git a/contrib/python/kiwisolver/py3/py/kiwisolver.cpp b/contrib/python/kiwisolver/py3/py/kiwisolver.cpp
index 54b333a2c8b..d82e67fde20 100644
--- a/contrib/python/kiwisolver/py3/py/kiwisolver.cpp
+++ b/contrib/python/kiwisolver/py3/py/kiwisolver.cpp
@@ -1,86 +1,187 @@
 /*-----------------------------------------------------------------------------
-| Copyright (c) 2013-2017, Nucleic Development Team.
+| Copyright (c) 2013-2019, Nucleic Development Team.
 |
 | Distributed under the terms of the Modified BSD License.
 |
-| The full license is in the file COPYING.txt, distributed with this software.
+| The full license is in the file LICENSE, distributed with this software.
 |----------------------------------------------------------------------------*/
-#include <Python.h>
+#include <cppy/cppy.h>
 #include <kiwi/kiwi.h>
-#include "pythonhelpers.h"
 #include "types.h"
 
-#define PY_KIWI_VERSION "1.1.0"
+#define PY_KIWI_VERSION "1.2.0"
+
+namespace
+{
+
+
+bool ready_types()
+{
+    using namespace kiwisolver;
+    if( !Variable::Ready() )
+    {
+        return false;
+    }
+    if( !Term::Ready() )
+    {
+        return false;
+    }
+    if( !Expression::Ready() )
+    {
+        return false;
+    }
+    if( !Constraint::Ready() )
+    {
+        return false;
+    }
+    if( !strength::Ready() )
+    {
+        return false;
+    }
+    if( !Solver::Ready() )
+    {
+        return false;
+    }
+    return true;
+}
+
+bool add_objects( PyObject* mod )
+{
+	using namespace kiwisolver;
+
+    cppy::ptr kiwiversion( PyUnicode_FromString( KIWI_VERSION ) );
+    if( !kiwiversion )
+    {
+        return false;
+    }
+    cppy::ptr pyversion( PyUnicode_FromString( PY_KIWI_VERSION ) );
+    if( !pyversion )
+    {
+        return false;
+    }
+    cppy::ptr pystrength( PyType_GenericNew( strength::TypeObject, 0, 0 ) );
+    if( !pystrength )
+    {
+        return false;
+    }
+
+    if( PyModule_AddObject( mod, "__version__", pyversion.get() ) < 0 )
+    {
+		return false;
+	}
+    pyversion.release();
+
+    if( PyModule_AddObject( mod, "__kiwi_version__", kiwiversion.get() ) < 0 )
+    {
+		return false;
+	}
+    kiwiversion.release();
+
+    if( PyModule_AddObject( mod, "strength", pystrength.get() ) < 0 )
+    {
+		return false;
+	}
+    pystrength.release();
+
+    // Variable
+    cppy::ptr var( pyobject_cast( Variable::TypeObject ) );
+	if( PyModule_AddObject( mod, "Variable", var.get() ) < 0 )
+	{
+		return false;
+	}
+    var.release();
+
+    // Term
+    cppy::ptr term( pyobject_cast( Term::TypeObject ) );
+	if( PyModule_AddObject( mod, "Term", term.get() ) < 0 )
+	{
+		return false;
+	}
+    term.release();
+
+    // Expression
+    cppy::ptr expr( pyobject_cast( Expression::TypeObject ) );
+	if( PyModule_AddObject( mod, "Expression", expr.get() ) < 0 )
+	{
+		return false;
+	}
+    expr.release();
+
+    // Constraint
+    cppy::ptr cons( pyobject_cast( Constraint::TypeObject ) );
+	if( PyModule_AddObject( mod, "Constraint", cons.get() ) < 0 )
+	{
+		return false;
+	}
+    cons.release();
+
+    cppy::ptr solver( pyobject_cast( Solver::TypeObject ) );
+	if( PyModule_AddObject( mod, "Solver", solver.get() ) < 0 )
+	{
+		return false;
+	}
+    solver.release();
+
+    PyModule_AddObject( mod, "DuplicateConstraint", DuplicateConstraint );
+    PyModule_AddObject( mod, "UnsatisfiableConstraint", UnsatisfiableConstraint );
+    PyModule_AddObject( mod, "UnknownConstraint", UnknownConstraint );
+    PyModule_AddObject( mod, "DuplicateEditVariable", DuplicateEditVariable );
+    PyModule_AddObject( mod, "UnknownEditVariable", UnknownEditVariable );
+    PyModule_AddObject( mod, "BadRequiredStrength", BadRequiredStrength );
+
+	return true;
+}
+
+
+int
+catom_modexec( PyObject *mod )
+{
+    if( !ready_types() )
+    {
+        return -1;
+    }
+    if( !kiwisolver::init_exceptions() )
+    {
+        return -1;
+    }
+    if( !add_objects( mod ) )
+    {
+        return -1;
+    }
+
+
+    return 0;
+}
 
-using namespace PythonHelpers;
 
 static PyMethodDef
 kiwisolver_methods[] = {
     { 0 } // Sentinel
 };
 
-#if PY_MAJOR_VERSION >= 3
-static struct PyModuleDef kiwisolver_moduledef = {
-    PyModuleDef_HEAD_INIT,
-    "kiwisolver",
-    NULL,
-    sizeof( struct module_state ),
-    kiwisolver_methods,
-    NULL
+
+PyModuleDef_Slot kiwisolver_slots[] = {
+    {Py_mod_exec, reinterpret_cast<void*>( catom_modexec ) },
+    {0, NULL}
 };
 
-PyMODINIT_FUNC
-PyInit_kiwisolver( void )
-#else
-PyMODINIT_FUNC
-initkiwisolver( void )
-#endif
+
+struct PyModuleDef moduledef = {
+        PyModuleDef_HEAD_INIT,
+        "kiwisolver",
+        "kiwisolver extension module",
+        0,
+        kiwisolver_methods,
+        kiwisolver_slots,
+        NULL,
+        NULL,
+        NULL
+};
+
+}  // namespace
+
+
+PyMODINIT_FUNC PyInit_kiwisolver( void )
 {
-#if PY_MAJOR_VERSION >= 3
-    PyObject *mod = PyModule_Create( &kiwisolver_moduledef );
-#else
-    PyObject* mod = Py_InitModule( "kiwisolver", kiwisolver_methods );
-#endif
-    if( !mod )
-        INITERROR;
-    if( import_variable() < 0 )
-        INITERROR;
-    if( import_term() < 0 )
-        INITERROR;
-    if( import_expression() < 0 )
-        INITERROR;
-    if( import_constraint() < 0 )
-        INITERROR;
-    if( import_solver() < 0 )
-        INITERROR;
-    if( import_strength() < 0 )
-        INITERROR;
-    PyObject* kiwiversion = FROM_STRING( KIWI_VERSION );
-    if( !kiwiversion )
-        INITERROR;
-    PyObject* pyversion = FROM_STRING( PY_KIWI_VERSION );
-    if( !pyversion )
-        INITERROR;
-    PyObject* pystrength = PyType_GenericNew( &strength_Type, 0, 0 );
-    if( !pystrength )
-        INITERROR;
-
-    PyModule_AddObject( mod, "__version__", pyversion );
-    PyModule_AddObject( mod, "__kiwi_version__", kiwiversion );
-    PyModule_AddObject( mod, "strength", pystrength );
-    PyModule_AddObject( mod, "Variable", newref( pyobject_cast( &Variable_Type ) ) );
-    PyModule_AddObject( mod, "Term", newref( pyobject_cast( &Term_Type ) ) );
-    PyModule_AddObject( mod, "Expression", newref( pyobject_cast( &Expression_Type ) ) );
-    PyModule_AddObject( mod, "Constraint", newref( pyobject_cast( &Constraint_Type ) ) );
-    PyModule_AddObject( mod, "Solver", newref( pyobject_cast( &Solver_Type ) ) );
-    PyModule_AddObject( mod, "DuplicateConstraint", newref( DuplicateConstraint ) );
-    PyModule_AddObject( mod, "UnsatisfiableConstraint", newref( UnsatisfiableConstraint ) );
-    PyModule_AddObject( mod, "UnknownConstraint", newref( UnknownConstraint ) );
-    PyModule_AddObject( mod, "DuplicateEditVariable", newref( DuplicateEditVariable ) );
-    PyModule_AddObject( mod, "UnknownEditVariable", newref( UnknownEditVariable ) );
-    PyModule_AddObject( mod, "BadRequiredStrength", newref( BadRequiredStrength ) );
-
-#if PY_MAJOR_VERSION >= 3
-    return mod;
-#endif
+    return PyModuleDef_Init( &moduledef );
 }
diff --git a/contrib/python/kiwisolver/py3/py/pythonhelpers.h b/contrib/python/kiwisolver/py3/py/pythonhelpers.h
deleted file mode 100644
index a9e0db634d7..00000000000
--- a/contrib/python/kiwisolver/py3/py/pythonhelpers.h
+++ /dev/null
@@ -1,771 +0,0 @@
-/*-----------------------------------------------------------------------------
-| Copyright (c) 2013-2017, Nucleic Development Team.
-|
-| Distributed under the terms of the Modified BSD License.
-|
-| The full license is in the file COPYING.txt, distributed with this software.
-|----------------------------------------------------------------------------*/
-#pragma once
-#include <Python.h>
-#include <structmember.h>
-#include <string>
-
-#if PY_MAJOR_VERSION >= 3
-#define FROM_STRING PyUnicode_FromString
-#define INITERROR return NULL
-#define MOD_INIT_FUNC(name) PyMODINIT_FUNC PyInit_##name(void)
-#else
-#define FROM_STRING PyString_FromString
-#define INITERROR return
-#define MOD_INIT_FUNC(name) PyMODINIT_FUNC init##name(void)
-#endif
-
-#ifndef Py_RETURN_NOTIMPLEMENTED
-#define Py_RETURN_NOTIMPLEMENTED \
-    return Py_INCREF(Py_NotImplemented), Py_NotImplemented
-#endif
-
-#define pyobject_cast( o ) ( reinterpret_cast<PyObject*>( o ) )
-#define pytype_cast( o ) ( reinterpret_cast<PyTypeObject*>( o ) )
-
-struct module_state {
-    PyObject *error;
-};
-
-
-namespace PythonHelpers
-{
-
-
-/*-----------------------------------------------------------------------------
-| Exception Handling
-|----------------------------------------------------------------------------*/
-inline PyObject*
-py_bad_internal_call( const char* message )
-{
-    PyErr_SetString( PyExc_SystemError, message );
-    return 0;
-}
-
-
-inline PyObject*
-py_type_fail( const char* message )
-{
-    PyErr_SetString( PyExc_TypeError, message );
-    return 0;
-}
-
-
-inline PyObject*
-py_expected_type_fail( PyObject* pyobj, const char* expected_type )
-{
-    PyErr_Format(
-        PyExc_TypeError,
-        "Expected object of type `%s`. Got object of type `%s` instead.",
-        expected_type, pyobj->ob_type->tp_name
-    );
-    return 0;
-}
-
-
-inline PyObject*
-py_value_fail( const char* message )
-{
-    PyErr_SetString( PyExc_ValueError, message );
-    return 0;
-}
-
-
-inline PyObject*
-py_runtime_fail( const char* message )
-{
-    PyErr_SetString( PyExc_RuntimeError, message );
-    return 0;
-}
-
-
-inline PyObject*
-py_attr_fail( const char* message )
-{
-    PyErr_SetString( PyExc_AttributeError, message );
-    return 0;
-}
-
-
-inline PyObject*
-py_no_attr_fail( PyObject* pyobj, const char* attr )
-{
-    PyErr_Format(
-        PyExc_AttributeError,
-        "'%s' object has no attribute '%s'",
-        pyobj->ob_type->tp_name, attr
-    );
-    return 0;
-}
-
-
-/*-----------------------------------------------------------------------------
-| Utilities
-|----------------------------------------------------------------------------*/
-inline PyObject*
-newref( PyObject* pyobj )
-{
-    Py_INCREF( pyobj );
-    return pyobj;
-}
-
-
-inline PyObject*
-xnewref( PyObject* pyobj )
-{
-    Py_XINCREF( pyobj );
-    return pyobj;
-}
-
-
-inline PyObject*
-py_bool( bool val )
-{
-    return newref( val ? Py_True : Py_False );
-}
-
-
-inline PyCFunction
-lookup_method( PyTypeObject* type, const char* name )
-{
-    PyMethodDef* method = type->tp_methods;
-    for( ; method->ml_name != 0; ++method )
-    {
-        if( strcmp( method->ml_name, name ) == 0 )
-            return method->ml_meth;
-    }
-    return 0;
-}
-
-
-/*-----------------------------------------------------------------------------
-| Object Ptr
-|----------------------------------------------------------------------------*/
-class PyObjectPtr {
-
-public:
-
-    PyObjectPtr() : m_pyobj( 0 ) {}
-
-    PyObjectPtr( const PyObjectPtr& objptr ) :
-        m_pyobj( PythonHelpers::xnewref( objptr.m_pyobj ) ) {}
-
-    PyObjectPtr( PyObject* pyobj ) : m_pyobj( pyobj ) {}
-
-    ~PyObjectPtr()
-    {
-        xdecref_release();
-    }
-
-    PyObject* get() const
-    {
-        return m_pyobj;
-    }
-
-    void set( PyObject* pyobj )
-    {
-        PyObject* old = m_pyobj;
-        m_pyobj = pyobj;
-        Py_XDECREF( old );
-    }
-
-    PyObject* release()
-    {
-        PyObject* pyobj = m_pyobj;
-        m_pyobj = 0;
-        return pyobj;
-    }
-
-    PyObject* decref_release()
-    {
-        PyObject* pyobj = m_pyobj;
-        m_pyobj = 0;
-        Py_DECREF( pyobj );
-        return pyobj;
-    }
-
-    PyObject* xdecref_release()
-    {
-        PyObject* pyobj = m_pyobj;
-        m_pyobj = 0;
-        Py_XDECREF( pyobj );
-        return pyobj;
-    }
-
-    PyObject* incref_release()
-    {
-        PyObject* pyobj = m_pyobj;
-        m_pyobj = 0;
-        Py_INCREF( pyobj );
-        return pyobj;
-    }
-
-    PyObject* xincref_release()
-    {
-        PyObject* pyobj = m_pyobj;
-        m_pyobj = 0;
-        Py_XINCREF( pyobj );
-        return pyobj;
-    }
-
-    void incref() const
-    {
-        Py_INCREF( m_pyobj );
-    }
-
-    void decref() const
-    {
-        Py_DECREF( m_pyobj );
-    }
-
-    void xincref() const
-    {
-        Py_XINCREF( m_pyobj );
-    }
-
-    void xdecref() const
-    {
-        Py_XDECREF( m_pyobj );
-    }
-
-    PyObject* newref() const
-    {
-        Py_INCREF( m_pyobj );
-        return m_pyobj;
-    }
-
-    PyObject* xnewref() const
-    {
-        Py_XINCREF( m_pyobj );
-        return m_pyobj;
-    }
-
-    size_t refcount() const
-    {
-        if( m_pyobj )
-            return m_pyobj->ob_refcnt;
-        return 0;
-    }
-
-    bool is_true( bool clear_err=true ) const
-    {
-        int truth = PyObject_IsTrue( m_pyobj );
-        if( truth == 1 )
-            return true;
-        if( truth == 0 )
-            return false;
-        if( clear_err )
-            PyErr_Clear();
-        return false;
-    }
-
-    bool is_None() const
-    {
-        return m_pyobj == Py_None;
-    }
-
-    bool is_True() const
-    {
-        return m_pyobj == Py_True;
-    }
-
-    bool is_False() const
-    {
-        return m_pyobj == Py_False;
-    }
-
-    bool load_dict( PyObjectPtr& out, bool forcecreate=false )
-    {
-        PyObject** dict = _PyObject_GetDictPtr( m_pyobj );
-        if( !dict )
-            return false;
-        if( forcecreate && !*dict )
-            *dict = PyDict_New();
-        out = PythonHelpers::xnewref( *dict );
-        return true;
-    }
-
-    bool richcompare( PyObject* other, int opid, bool clear_err=true )
-    {
-        int r = PyObject_RichCompareBool( m_pyobj, other, opid );
-        if( r == 1 )
-            return true;
-        if( r == 0 )
-            return false;
-        if( clear_err && PyErr_Occurred() )
-            PyErr_Clear();
-        return false;
-    }
-
-    bool richcompare( PyObjectPtr& other, int opid, bool clear_err=true )
-    {
-        return richcompare( other.m_pyobj, opid, clear_err );
-    }
-
-    bool hasattr( PyObject* attr )
-    {
-        return PyObject_HasAttr( m_pyobj, attr ) == 1;
-    }
-
-    bool hasattr( PyObjectPtr& attr )
-    {
-        return PyObject_HasAttr( m_pyobj, attr.get() ) == 1;
-    }
-
-    bool hasattr( const char* attr )
-    {
-        return PyObject_HasAttrString( m_pyobj, attr ) == 1;
-    }
-
-    bool hasattr( std::string& attr )
-    {
-        return hasattr( attr.c_str() );
-    }
-
-    PyObjectPtr getattr( PyObject* attr )
-    {
-        return PyObjectPtr( PyObject_GetAttr( m_pyobj, attr ) );
-    }
-
-    PyObjectPtr getattr( PyObjectPtr& attr )
-    {
-        return PyObjectPtr( PyObject_GetAttr( m_pyobj, attr.get() ) );
-    }
-
-    PyObjectPtr getattr( const char* attr )
-    {
-        return PyObjectPtr( PyObject_GetAttrString( m_pyobj, attr ) );
-    }
-
-    PyObjectPtr getattr( std::string& attr )
-    {
-        return getattr( attr.c_str() );
-    }
-
-    bool setattr( PyObject* attr, PyObject* value )
-    {
-        return PyObject_SetAttr( m_pyobj, attr, value ) == 0;
-    }
-
-    bool setattr( PyObjectPtr& attr, PyObjectPtr& value )
-    {
-        return PyObject_SetAttr( m_pyobj, attr.get(), value.get() ) == 0;
-    }
-
-    PyObjectPtr operator()( PyObjectPtr& args ) const
-    {
-        return PyObjectPtr( PyObject_Call( m_pyobj, args.get(), 0 ) );
-    }
-
-    PyObjectPtr operator()( PyObjectPtr& args, PyObjectPtr& kwargs ) const
-    {
-        return PyObjectPtr( PyObject_Call( m_pyobj, args.get(), kwargs.get() ) );
-    }
-
-    operator void*() const
-    {
-        return static_cast<void*>( m_pyobj );
-    }
-
-    PyObjectPtr& operator=( const PyObjectPtr& rhs )
-    {
-        PyObject* old = m_pyobj;
-        m_pyobj = rhs.m_pyobj;
-        Py_XINCREF( m_pyobj );
-        Py_XDECREF( old );
-        return *this;
-    }
-
-    PyObjectPtr& operator=( PyObject* rhs )
-    {
-        PyObject* old = m_pyobj;
-        m_pyobj = rhs;
-        Py_XDECREF( old );
-        return *this;
-    }
-
-protected:
-
-    PyObject* m_pyobj;
-
-};
-
-
-inline bool
-operator!=( const PyObjectPtr& lhs, const PyObjectPtr& rhs )
-{
-    return lhs.get() != rhs.get();
-}
-
-
-inline bool
-operator!=( const PyObject* lhs, const PyObjectPtr& rhs )
-{
-    return lhs != rhs.get();
-}
-
-
-inline bool
-operator!=( const PyObjectPtr& lhs, const PyObject* rhs )
-{
-    return lhs.get() != rhs;
-}
-
-
-inline bool
-operator==( const PyObjectPtr& lhs, const PyObjectPtr& rhs )
-{
-    return lhs.get() == rhs.get();
-}
-
-
-inline bool
-operator==( const PyObject* lhs, const PyObjectPtr& rhs )
-{
-    return lhs == rhs.get();
-}
-
-
-inline bool
-operator==( const PyObjectPtr& lhs, const PyObject* rhs )
-{
-    return lhs.get() == rhs;
-}
-
-
-/*-----------------------------------------------------------------------------
-| Tuple Ptr
-|----------------------------------------------------------------------------*/
-class PyTuplePtr : public PyObjectPtr {
-
-public:
-
-    PyTuplePtr() : PyObjectPtr() {}
-
-    PyTuplePtr( const PyObjectPtr& objptr ) : PyObjectPtr( objptr ) {}
-
-    PyTuplePtr( PyObject* pytuple ) : PyObjectPtr( pytuple ) {}
-
-    bool check()
-    {
-        return PyTuple_Check( m_pyobj );
-    }
-
-    bool check_exact()
-    {
-        return PyTuple_CheckExact( m_pyobj );
-    }
-
-    Py_ssize_t size() const
-    {
-        return PyTuple_GET_SIZE( m_pyobj );
-    }
-
-    PyObjectPtr get_item( Py_ssize_t index ) const
-    {
-        return PyObjectPtr( PythonHelpers::newref( PyTuple_GET_ITEM( m_pyobj, index ) ) );
-    }
-
-    void set_item( Py_ssize_t index, PyObject* pyobj )
-    {
-        PyObject* old_item = PyTuple_GET_ITEM( m_pyobj, index );
-        PyTuple_SET_ITEM( m_pyobj, index, pyobj );
-        Py_XDECREF( old_item );
-    }
-
-    void set_item( Py_ssize_t index, PyObjectPtr& item )
-    {
-        PyObject* old_item = PyTuple_GET_ITEM( m_pyobj, index );
-        PyTuple_SET_ITEM( m_pyobj, index, item.get() );
-        Py_XINCREF( item.get() );
-        Py_XDECREF( old_item );
-    }
-
-    // pyobj must not be null, only use to fill a new empty tuple
-    void initialize( Py_ssize_t index, PyObject* pyobj )
-    {
-        PyTuple_SET_ITEM( m_pyobj, index, pyobj );
-    }
-
-    // ptr must not be empty, only use to fill a new empty tuple
-    void initialize( Py_ssize_t index, PyObjectPtr& item )
-    {
-        PyTuple_SET_ITEM( m_pyobj, index, item.get() );
-        Py_INCREF( item.get() );
-    }
-
-};
-
-
-/*-----------------------------------------------------------------------------
-| List Ptr
-|----------------------------------------------------------------------------*/
-class PyListPtr : public PyObjectPtr {
-
-public:
-
-    PyListPtr() : PyObjectPtr() {}
-
-    PyListPtr( const PyObjectPtr& objptr ) : PyObjectPtr( objptr ) {}
-
-    PyListPtr( PyObject* pylist ) : PyObjectPtr( pylist ) {}
-
-    bool check() const
-    {
-        return PyList_Check( m_pyobj );
-    }
-
-    bool check_exact() const
-    {
-        return PyList_CheckExact( m_pyobj );
-    }
-
-    Py_ssize_t size() const
-    {
-        return PyList_GET_SIZE( m_pyobj );
-    }
-
-    PyObject* borrow_item( Py_ssize_t index ) const
-    {
-        return PyList_GET_ITEM( m_pyobj, index );
-    }
-
-    PyObjectPtr get_item( Py_ssize_t index ) const
-    {
-        return PyObjectPtr( PythonHelpers::newref( PyList_GET_ITEM( m_pyobj, index ) ) );
-    }
-
-    void set_item( Py_ssize_t index, PyObject* pyobj ) const
-    {
-        PyObject* old_item = PyList_GET_ITEM( m_pyobj, index );
-        PyList_SET_ITEM( m_pyobj, index, pyobj );
-        Py_XDECREF( old_item );
-    }
-
-    void set_item( Py_ssize_t index, PyObjectPtr& item ) const
-    {
-        PyObject* old_item = PyList_GET_ITEM( m_pyobj, index );
-        PyList_SET_ITEM( m_pyobj, index, item.get() );
-        Py_XINCREF( item.get() );
-        Py_XDECREF( old_item );
-    }
-
-    bool del_item( Py_ssize_t index ) const
-    {
-        if( PySequence_DelItem( m_pyobj, index ) == -1 )
-            return false;
-        return true;
-    }
-
-    bool append( PyObjectPtr& pyobj ) const
-    {
-        if( PyList_Append( m_pyobj, pyobj.get() ) == 0 )
-            return true;
-        return false;
-    }
-
-    Py_ssize_t index( PyObjectPtr& item ) const
-    {
-        Py_ssize_t maxidx = size();
-        for( Py_ssize_t idx = 0; idx < maxidx; idx++ )
-        {
-            PyObjectPtr other( get_item( idx ) );
-            if( item.richcompare( other, Py_EQ ) )
-                return idx;
-        }
-        return -1;
-    }
-
-};
-
-
-/*-----------------------------------------------------------------------------
-| Dict Ptr
-|----------------------------------------------------------------------------*/
-class PyDictPtr : public PyObjectPtr {
-
-public:
-
-    PyDictPtr() : PyObjectPtr() {}
-
-    PyDictPtr( const PyObjectPtr& objptr ) : PyObjectPtr( objptr ) {}
-
-    PyDictPtr( PyObject* pydict ) : PyObjectPtr( pydict ) {}
-
-    bool check()
-    {
-        return PyDict_Check( m_pyobj );
-    }
-
-    bool check_exact()
-    {
-        return PyDict_CheckExact( m_pyobj );
-    }
-
-    Py_ssize_t size() const
-    {
-        return PyDict_Size( m_pyobj );
-    }
-
-    PyObjectPtr get_item( PyObject* key ) const
-    {
-        return PyObjectPtr( PythonHelpers::xnewref( PyDict_GetItem( m_pyobj, key ) ) ) ;
-    }
-
-    PyObjectPtr get_item( PyObjectPtr& key ) const
-    {
-        return PyObjectPtr( PythonHelpers::xnewref( PyDict_GetItem( m_pyobj, key.get() ) ) );
-    }
-
-    PyObjectPtr get_item( const char* key ) const
-    {
-        return PyObjectPtr( PythonHelpers::xnewref( PyDict_GetItemString( m_pyobj, key ) ) );
-    }
-
-    PyObjectPtr get_item( std::string& key ) const
-    {
-        return get_item( key.c_str() );
-    }
-
-    bool set_item( PyObject* key, PyObject* value ) const
-    {
-        if( PyDict_SetItem( m_pyobj, key, value ) == 0 )
-            return true;
-        return false;
-    }
-
-    bool set_item( PyObject* key, PyObjectPtr& value ) const
-    {
-        if( PyDict_SetItem( m_pyobj, key, value.get() ) == 0 )
-            return true;
-        return false;
-    }
-
-    bool set_item( PyObjectPtr& key, PyObject* value ) const
-    {
-        if( PyDict_SetItem( m_pyobj, key.get(), value ) == 0 )
-            return true;
-        return false;
-    }
-
-    bool set_item( PyObjectPtr& key, PyObjectPtr& value ) const
-    {
-        if( PyDict_SetItem( m_pyobj, key.get(), value.get() ) == 0 )
-            return true;
-        return false;
-    }
-
-    bool set_item( const char* key, PyObjectPtr& value ) const
-    {
-        if( PyDict_SetItemString( m_pyobj, key, value.get() ) == 0 )
-            return true;
-        return false;
-    }
-
-    bool set_item( const char* key, PyObject* value ) const
-    {
-        if( PyDict_SetItemString( m_pyobj, key, value ) == 0 )
-            return true;
-        return false;
-    }
-
-    bool set_item( std::string& key, PyObjectPtr& value ) const
-    {
-        return set_item( key.c_str(), value );
-    }
-
-    bool del_item( PyObjectPtr& key ) const
-    {
-        if( PyDict_DelItem( m_pyobj, key.get() ) == 0 )
-            return true;
-        return false;
-    }
-
-    bool del_item( const char* key ) const
-    {
-        if( PyDict_DelItemString( m_pyobj, key ) == 0 )
-            return true;
-        return false;
-    }
-
-    bool del_item( std::string& key ) const
-    {
-        return del_item( key.c_str() );
-    }
-
-};
-
-
-/*-----------------------------------------------------------------------------
-| Method Ptr
-|----------------------------------------------------------------------------*/
-class PyMethodPtr : public PyObjectPtr {
-
-public:
-
-    PyMethodPtr() : PyObjectPtr() {}
-
-    PyMethodPtr( const PyObjectPtr& objptr ) : PyObjectPtr( objptr ) {}
-
-    PyMethodPtr( PyObject* pymethod ) : PyObjectPtr( pymethod ) {}
-
-    bool check()
-    {
-        return PyMethod_Check( m_pyobj );
-    }
-
-    PyObjectPtr get_self() const
-    {
-        return PyObjectPtr( PythonHelpers::xnewref( PyMethod_GET_SELF( m_pyobj ) ) );
-    }
-
-    PyObjectPtr get_function() const
-    {
-        return PyObjectPtr( PythonHelpers::xnewref( PyMethod_GET_FUNCTION( m_pyobj ) ) );
-    }
-
-#if PY_MAJOR_VERSION < 3
-    PyObjectPtr get_class() const
-    {
-        return PyObjectPtr( PythonHelpers::xnewref( PyMethod_GET_CLASS( m_pyobj ) ) );
-    }
-#endif
-};
-
-
-/*-----------------------------------------------------------------------------
-| Weakref Ptr
-|----------------------------------------------------------------------------*/
-class PyWeakrefPtr : public PyObjectPtr {
-
-public:
-
-    PyWeakrefPtr() : PyObjectPtr() {}
-
-    PyWeakrefPtr( const PyObjectPtr& objptr ) : PyObjectPtr( objptr ) {}
-
-    PyWeakrefPtr( PyObject* pyweakref ) : PyObjectPtr( pyweakref ) {}
-
-    bool check()
-    {
-        return PyWeakref_CheckRef( m_pyobj );
-    }
-
-    bool check_exact()
-    {
-        return PyWeakref_CheckRefExact( m_pyobj );
-    }
-
-    PyObjectPtr get_object() const
-    {
-        return PyObjectPtr( PythonHelpers::newref( PyWeakref_GET_OBJECT( m_pyobj ) ) );
-    }
-
-};
-
-} // namespace PythonHelpers
diff --git a/contrib/python/kiwisolver/py3/py/solver.cpp b/contrib/python/kiwisolver/py3/py/solver.cpp
index 7a2ef23ca33..cd6af8c724d 100644
--- a/contrib/python/kiwisolver/py3/py/solver.cpp
+++ b/contrib/python/kiwisolver/py3/py/solver.cpp
@@ -1,25 +1,27 @@
 /*-----------------------------------------------------------------------------
-| Copyright (c) 2013-2017, Nucleic Development Team.
+| Copyright (c) 2013-2019, Nucleic Development Team.
 |
 | Distributed under the terms of the Modified BSD License.
 |
-| The full license is in the file COPYING.txt, distributed with this software.
+| The full license is in the file LICENSE, distributed with this software.
 |----------------------------------------------------------------------------*/
-#include <Python.h>
+#include <cppy/cppy.h>
 #include <kiwi/kiwi.h>
-#include "pythonhelpers.h"
 #include "types.h"
 #include "util.h"
 
 
-using namespace PythonHelpers;
+namespace kiwisolver
+{
 
+namespace
+{
 
-static PyObject*
+PyObject*
 Solver_new( PyTypeObject* type, PyObject* args, PyObject* kwargs )
 {
 	if( PyTuple_GET_SIZE( args ) != 0 || ( kwargs && PyDict_Size( kwargs ) != 0 ) )
-		return py_type_fail( "Solver.__new__ takes no arguments" );
+		return cppy::type_error( "Solver.__new__ takes no arguments" );
 	PyObject* pysolver = PyType_GenericNew( type, args, kwargs );
 	if( !pysolver )
 		return 0;
@@ -29,7 +31,7 @@ Solver_new( PyTypeObject* type, PyObject* args, PyObject* kwargs )
 }
 
 
-static void
+void
 Solver_dealloc( Solver* self )
 {
 	self->solver.~Solver();
@@ -37,11 +39,11 @@ Solver_dealloc( Solver* self )
 }
 
 
-static PyObject*
+PyObject*
 Solver_addConstraint( Solver* self, PyObject* other )
 {
 	if( !Constraint::TypeCheck( other ) )
-		return py_expected_type_fail( other, "Constraint" );
+		return cppy::type_error( other, "Constraint" );
 	Constraint* cn = reinterpret_cast<Constraint*>( other );
 	try
 	{
@@ -61,11 +63,11 @@ Solver_addConstraint( Solver* self, PyObject* other )
 }
 
 
-static PyObject*
+PyObject*
 Solver_removeConstraint( Solver* self, PyObject* other )
 {
 	if( !Constraint::TypeCheck( other ) )
-		return py_expected_type_fail( other, "Constraint" );
+		return cppy::type_error( other, "Constraint" );
 	Constraint* cn = reinterpret_cast<Constraint*>( other );
 	try
 	{
@@ -80,17 +82,17 @@ Solver_removeConstraint( Solver* self, PyObject* other )
 }
 
 
-static PyObject*
+PyObject*
 Solver_hasConstraint( Solver* self, PyObject* other )
 {
 	if( !Constraint::TypeCheck( other ) )
-		return py_expected_type_fail( other, "Constraint" );
+		return cppy::type_error( other, "Constraint" );
 	Constraint* cn = reinterpret_cast<Constraint*>( other );
-	return newref( self->solver.hasConstraint( cn->constraint ) ? Py_True : Py_False );
+	return cppy::incref( self->solver.hasConstraint( cn->constraint ) ? Py_True : Py_False );
 }
 
 
-static PyObject*
+PyObject*
 Solver_addEditVariable( Solver* self, PyObject* args )
 {
 	PyObject* pyvar;
@@ -98,7 +100,7 @@ Solver_addEditVariable( Solver* self, PyObject* args )
 	if( !PyArg_ParseTuple( args, "OO", &pyvar, &pystrength ) )
 		return 0;
 	if( !Variable::TypeCheck( pyvar ) )
-		return py_expected_type_fail( pyvar, "Variable" );
+		return cppy::type_error( pyvar, "Variable" );
 	double strength;
 	if( !convert_to_strength( pystrength, strength ) )
 		return 0;
@@ -121,11 +123,11 @@ Solver_addEditVariable( Solver* self, PyObject* args )
 }
 
 
-static PyObject*
+PyObject*
 Solver_removeEditVariable( Solver* self, PyObject* other )
 {
 	if( !Variable::TypeCheck( other ) )
-		return py_expected_type_fail( other, "Variable" );
+		return cppy::type_error( other, "Variable" );
 	Variable* var = reinterpret_cast<Variable*>( other );
 	try
 	{
@@ -140,17 +142,17 @@ Solver_removeEditVariable( Solver* self, PyObject* other )
 }
 
 
-static PyObject*
+PyObject*
 Solver_hasEditVariable( Solver* self, PyObject* other )
 {
 	if( !Variable::TypeCheck( other ) )
-		return py_expected_type_fail( other, "Variable" );
+		return cppy::type_error( other, "Variable" );
 	Variable* var = reinterpret_cast<Variable*>( other );
-	return newref( self->solver.hasEditVariable( var->variable ) ? Py_True : Py_False );
+	return cppy::incref( self->solver.hasEditVariable( var->variable ) ? Py_True : Py_False );
 }
 
 
-static PyObject*
+PyObject*
 Solver_suggestValue( Solver* self, PyObject* args )
 {
 	PyObject* pyvar;
@@ -158,7 +160,7 @@ Solver_suggestValue( Solver* self, PyObject* args )
 	if( !PyArg_ParseTuple( args, "OO", &pyvar, &pyvalue ) )
 		return 0;
 	if( !Variable::TypeCheck( pyvar ) )
-		return py_expected_type_fail( pyvar, "Variable" );
+		return cppy::type_error( pyvar, "Variable" );
 	double value;
 	if( !convert_to_double( pyvalue, value ) )
 		return 0;
@@ -176,7 +178,7 @@ Solver_suggestValue( Solver* self, PyObject* args )
 }
 
 
-static PyObject*
+PyObject*
 Solver_updateVariables( Solver* self )
 {
 	self->solver.updateVariables();
@@ -184,7 +186,7 @@ Solver_updateVariables( Solver* self )
 }
 
 
-static PyObject*
+PyObject*
 Solver_reset( Solver* self )
 {
 	self->solver.reset();
@@ -192,15 +194,15 @@ Solver_reset( Solver* self )
 }
 
 
-static PyObject*
+PyObject*
 Solver_dump( Solver* self )
 {
-	PyObjectPtr dump_str( PyUnicode_FromString( self->solver.dumps().c_str() ) );
+	cppy::ptr dump_str( PyUnicode_FromString( self->solver.dumps().c_str() ) );
 	PyObject_Print( dump_str.get(), stdout, 0 );
 	Py_RETURN_NONE;
 }
 
-static PyObject*
+PyObject*
 Solver_dumps( Solver* self )
 {
 	return PyUnicode_FromString( self->solver.dumps().c_str() );
@@ -234,62 +236,45 @@ Solver_methods[] = {
 };
 
 
-PyTypeObject Solver_Type = {
-	PyVarObject_HEAD_INIT( &PyType_Type, 0 )
-	"kiwisolver.Solver",                    /* tp_name */
-	sizeof( Solver ),                       /* tp_basicsize */
-	0,                                      /* tp_itemsize */
-	(destructor)Solver_dealloc,             /* tp_dealloc */
-	(printfunc)0,                           /* tp_print */
-	(getattrfunc)0,                         /* tp_getattr */
-	(setattrfunc)0,                         /* tp_setattr */
-#if PY_VERSION_HEX >= 0x03050000
-	( PyAsyncMethods* )0,                   /* tp_as_async */
-#elif PY_VERSION_HEX >= 0x03000000
-	( void* ) 0,                            /* tp_reserved */
-#else
-	( cmpfunc )0,                           /* tp_compare */
-#endif
-	(reprfunc)0,                            /* tp_repr */
-	(PyNumberMethods*)0,                    /* tp_as_number */
-	(PySequenceMethods*)0,                  /* tp_as_sequence */
-	(PyMappingMethods*)0,                   /* tp_as_mapping */
-	(hashfunc)0,                            /* tp_hash */
-	(ternaryfunc)0,                         /* tp_call */
-	(reprfunc)0,                            /* tp_str */
-	(getattrofunc)0,                        /* tp_getattro */
-	(setattrofunc)0,                        /* tp_setattro */
-	(PyBufferProcs*)0,                      /* tp_as_buffer */
-	Py_TPFLAGS_DEFAULT|Py_TPFLAGS_BASETYPE, /* tp_flags */
-	0,                                      /* Documentation string */
-	(traverseproc)0,                        /* tp_traverse */
-	(inquiry)0,                             /* tp_clear */
-	(richcmpfunc)0,                         /* tp_richcompare */
-	0,                                      /* tp_weaklistoffset */
-	(getiterfunc)0,                         /* tp_iter */
-	(iternextfunc)0,                        /* tp_iternext */
-	(struct PyMethodDef*)Solver_methods,    /* tp_methods */
-	(struct PyMemberDef*)0,                 /* tp_members */
-	0,                                      /* tp_getset */
-	0,                                      /* tp_base */
-	0,                                      /* tp_dict */
-	(descrgetfunc)0,                        /* tp_descr_get */
-	(descrsetfunc)0,                        /* tp_descr_set */
-	0,                                      /* tp_dictoffset */
-	(initproc)0,                            /* tp_init */
-	(allocfunc)PyType_GenericAlloc,         /* tp_alloc */
-	(newfunc)Solver_new,                    /* tp_new */
-	(freefunc)PyObject_Del,                 /* tp_free */
-	(inquiry)0,                             /* tp_is_gc */
-	0,                                      /* tp_bases */
-	0,                                      /* tp_mro */
-	0,                                      /* tp_cache */
-	0,                                      /* tp_subclasses */
-	0,                                      /* tp_weaklist */
-	(destructor)0                           /* tp_del */
+static PyType_Slot Solver_Type_slots[] = {
+    { Py_tp_dealloc, void_cast( Solver_dealloc ) },      /* tp_dealloc */
+    { Py_tp_methods, void_cast( Solver_methods ) },      /* tp_methods */
+    { Py_tp_new, void_cast( Solver_new ) },              /* tp_new */
+    { Py_tp_alloc, void_cast( PyType_GenericAlloc ) },   /* tp_alloc */
+    { Py_tp_free, void_cast( PyObject_Del ) },           /* tp_free */
+    { 0, 0 },
+};
+
+
+} // namespace
+
+
+// Initialize static variables (otherwise the compiler eliminates them)
+PyTypeObject* Solver::TypeObject = NULL;
+
+
+PyType_Spec Solver::TypeObject_Spec = {
+	"kiwisolver.Solver",             /* tp_name */
+	sizeof( Solver ),                /* tp_basicsize */
+	0,                                   /* tp_itemsize */
+	Py_TPFLAGS_DEFAULT|
+    Py_TPFLAGS_BASETYPE,                 /* tp_flags */
+    Solver_Type_slots                /* slots */
 };
 
 
+bool Solver::Ready()
+{
+    // The reference will be handled by the module to which we will add the type
+	TypeObject = pytype_cast( PyType_FromSpec( &TypeObject_Spec ) );
+    if( !TypeObject )
+    {
+        return false;
+    }
+    return true;
+}
+
+
 PyObject* DuplicateConstraint;
 
 PyObject* UnsatisfiableConstraint;
@@ -303,31 +288,51 @@ PyObject* UnknownEditVariable;
 PyObject* BadRequiredStrength;
 
 
-int import_solver()
+bool init_exceptions()
 {
  	DuplicateConstraint = PyErr_NewException(
  		const_cast<char*>( "kiwisolver.DuplicateConstraint" ), 0, 0 );
  	if( !DuplicateConstraint )
- 		return -1;
+    {
+        return false;
+    }
+
   	UnsatisfiableConstraint = PyErr_NewException(
   		const_cast<char*>( "kiwisolver.UnsatisfiableConstraint" ), 0, 0 );
  	if( !UnsatisfiableConstraint )
- 		return -1;
+ 	{
+        return false;
+    }
+
   	UnknownConstraint = PyErr_NewException(
   		const_cast<char*>( "kiwisolver.UnknownConstraint" ), 0, 0 );
  	if( !UnknownConstraint )
- 		return -1;
+ 	{
+        return false;
+    }
+
   	DuplicateEditVariable = PyErr_NewException(
   		const_cast<char*>( "kiwisolver.DuplicateEditVariable" ), 0, 0 );
  	if( !DuplicateEditVariable )
- 		return -1;
+ 	{
+        return false;
+    }
+
   	UnknownEditVariable = PyErr_NewException(
   		const_cast<char*>( "kiwisolver.UnknownEditVariable" ), 0, 0 );
  	if( !UnknownEditVariable )
- 		return -1;
+ 	{
+        return false;
+    }
+
   	BadRequiredStrength = PyErr_NewException(
   		const_cast<char*>( "kiwisolver.BadRequiredStrength" ), 0, 0 );
  	if( !BadRequiredStrength )
- 		return -1;
-	return PyType_Ready( &Solver_Type );
+ 	{
+        return false;
+    }
+
+	return true;
 }
+
+}  // namespace
diff --git a/contrib/python/kiwisolver/py3/py/strength.cpp b/contrib/python/kiwisolver/py3/py/strength.cpp
index df1552d1947..03611311f9a 100644
--- a/contrib/python/kiwisolver/py3/py/strength.cpp
+++ b/contrib/python/kiwisolver/py3/py/strength.cpp
@@ -1,61 +1,68 @@
 /*-----------------------------------------------------------------------------
-| Copyright (c) 2013-2017, Nucleic Development Team.
+| Copyright (c) 2013-2019, Nucleic Development Team.
 |
 | Distributed under the terms of the Modified BSD License.
 |
-| The full license is in the file COPYING.txt, distributed with this software.
+| The full license is in the file LICENSE, distributed with this software.
 |----------------------------------------------------------------------------*/
-#include <Python.h>
+#include <cppy/cppy.h>
 #include <kiwi/kiwi.h>
-#include "pythonhelpers.h"
 #include "util.h"
 
 
-using namespace PythonHelpers;
+#ifdef __clang__
+#pragma clang diagnostic ignored "-Wdeprecated-writable-strings"
+#endif
+
+#ifdef __GNUC__
+#pragma GCC diagnostic ignored "-Wwrite-strings"
+#endif
 
 
-struct strength
+namespace kiwisolver
 {
-	PyObject_HEAD;
-};
 
 
-static void
+namespace
+{
+
+
+void
 strength_dealloc( PyObject* self )
 {
 	Py_TYPE( self )->tp_free( self );
 }
 
 
-static PyObject*
+PyObject*
 strength_weak( strength* self )
 {
 	return PyFloat_FromDouble( kiwi::strength::weak );
 }
 
 
-static PyObject*
+PyObject*
 strength_medium( strength* self )
 {
 	return PyFloat_FromDouble( kiwi::strength::medium );
 }
 
 
-static PyObject*
+PyObject*
 strength_strong( strength* self )
 {
 	return PyFloat_FromDouble( kiwi::strength::strong );
 }
 
 
-static PyObject*
+PyObject*
 strength_required( strength* self )
 {
 	return PyFloat_FromDouble( kiwi::strength::required );
 }
 
 
-static PyObject*
+PyObject*
 strength_create( strength* self, PyObject* args )
 {
 	PyObject* pya;
@@ -100,63 +107,43 @@ strength_methods[] = {
 };
 
 
-PyTypeObject strength_Type = {
-	PyVarObject_HEAD_INIT( &PyType_Type, 0 )
-	"kiwisolver.strength",                  /* tp_name */
-	sizeof( strength ),                     /* tp_basicsize */
-	0,                                      /* tp_itemsize */
-	(destructor)strength_dealloc,           /* tp_dealloc */
-	(printfunc)0,                           /* tp_print */
-	(getattrfunc)0,                         /* tp_getattr */
-	(setattrfunc)0,                         /* tp_setattr */
-#if PY_VERSION_HEX >= 0x03050000
-	( PyAsyncMethods* )0,                   /* tp_as_async */
-#elif PY_VERSION_HEX >= 0x03000000
-	( void* ) 0,                            /* tp_reserved */
-#else
-	( cmpfunc )0,                           /* tp_compare */
-#endif
-	(reprfunc)0,                            /* tp_repr */
-	(PyNumberMethods*)0,                    /* tp_as_number */
-	(PySequenceMethods*)0,                  /* tp_as_sequence */
-	(PyMappingMethods*)0,                   /* tp_as_mapping */
-	(hashfunc)0,                            /* tp_hash */
-	(ternaryfunc)0,                         /* tp_call */
-	(reprfunc)0,                            /* tp_str */
-	(getattrofunc)0,                        /* tp_getattro */
-	(setattrofunc)0,                        /* tp_setattro */
-	(PyBufferProcs*)0,                      /* tp_as_buffer */
-	Py_TPFLAGS_DEFAULT,                     /* tp_flags */
-	0,                                      /* Documentation string */
-	(traverseproc)0,                        /* tp_traverse */
-	(inquiry)0,                             /* tp_clear */
-	(richcmpfunc)0,                         /* tp_richcompare */
-	0,                                      /* tp_weaklistoffset */
-	(getiterfunc)0,                         /* tp_iter */
-	(iternextfunc)0,                        /* tp_iternext */
-	(struct PyMethodDef*)strength_methods,  /* tp_methods */
-	(struct PyMemberDef*)0,                 /* tp_members */
-	strength_getset,                        /* tp_getset */
-	0,                                      /* tp_base */
-	0,                                      /* tp_dict */
-	(descrgetfunc)0,                        /* tp_descr_get */
-	(descrsetfunc)0,                        /* tp_descr_set */
-	0,                                      /* tp_dictoffset */
-	(initproc)0,                            /* tp_init */
-	(allocfunc)PyType_GenericAlloc,         /* tp_alloc */
-	(newfunc)0,                             /* tp_new */
-	(freefunc)PyObject_Del,                 /* tp_free */
-	(inquiry)0,                             /* tp_is_gc */
-	0,                                      /* tp_bases */
-	0,                                      /* tp_mro */
-	0,                                      /* tp_cache */
-	0,                                      /* tp_subclasses */
-	0,                                      /* tp_weaklist */
-	(destructor)0                           /* tp_del */
+
+static PyType_Slot strength_Type_slots[] = {
+    { Py_tp_dealloc, void_cast( strength_dealloc ) },      /* tp_dealloc */
+    { Py_tp_getset, void_cast( strength_getset ) },        /* tp_getset */
+    { Py_tp_methods, void_cast( strength_methods ) },      /* tp_methods */
+    { Py_tp_alloc, void_cast( PyType_GenericAlloc ) },     /* tp_alloc */
+    { Py_tp_free, void_cast( PyObject_Del ) },          /* tp_free */
+    { 0, 0 },
 };
 
 
-int import_strength()
+} // namespace
+
+
+// Initialize static variables (otherwise the compiler eliminates them)
+PyTypeObject* strength::TypeObject = NULL;
+
+
+PyType_Spec strength::TypeObject_Spec = {
+	"kiwisolver.strength",             /* tp_name */
+	sizeof( strength ),                /* tp_basicsize */
+	0,                                 /* tp_itemsize */
+	Py_TPFLAGS_DEFAULT,                /* tp_flags */
+    strength_Type_slots                /* slots */
+};
+
+
+bool strength::Ready()
 {
-	return PyType_Ready( &strength_Type );
+    // The reference will be handled by the module to which we will add the type
+	TypeObject = pytype_cast( PyType_FromSpec( &TypeObject_Spec ) );
+    if( !TypeObject )
+    {
+        return false;
+    }
+    return true;
 }
+
+
+}  // namespace
diff --git a/contrib/python/kiwisolver/py3/py/symbolics.h b/contrib/python/kiwisolver/py3/py/symbolics.h
index ac575537403..69ea5404c7e 100644
--- a/contrib/python/kiwisolver/py3/py/symbolics.h
+++ b/contrib/python/kiwisolver/py3/py/symbolics.h
@@ -1,17 +1,19 @@
 /*-----------------------------------------------------------------------------
-| Copyright (c) 2013-2017, Nucleic Development Team.
+| Copyright (c) 2013-2019, Nucleic Development Team.
 |
 | Distributed under the terms of the Modified BSD License.
 |
-| The full license is in the file COPYING.txt, distributed with this software.
+| The full license is in the file LICENSE, distributed with this software.
 |----------------------------------------------------------------------------*/
 #pragma once
-#include <Python.h>
-#include "pythonhelpers.h"
+#include <cppy/cppy.h>
 #include "types.h"
 #include "util.h"
 
 
+namespace kiwisolver
+{
+
 template<typename Op, typename T>
 struct UnaryInvoke
 {
@@ -61,10 +63,6 @@ struct BinaryInvoke
 			return Invk()( primary, reinterpret_cast<Variable*>( secondary ) );
 		if( PyFloat_Check( secondary ) )
 			return Invk()( primary, PyFloat_AS_DOUBLE( secondary ) );
-#if PY_MAJOR_VERSION < 3
-		if( PyInt_Check( secondary ) )
-			return Invk()( primary, double( PyInt_AS_LONG( secondary ) ) );
-#endif
 		if( PyLong_Check( secondary ) )
 		{
 			double v = PyLong_AsDouble( secondary );
@@ -90,11 +88,11 @@ struct BinaryMul
 template<> inline
 PyObject* BinaryMul::operator()( Variable* first, double second )
 {
-	PyObject* pyterm = PyType_GenericNew( &Term_Type, 0, 0 );
+	PyObject* pyterm = PyType_GenericNew( Term::TypeObject, 0, 0 );
 	if( !pyterm )
 		return 0;
 	Term* term = reinterpret_cast<Term*>( pyterm );
-	term->variable = PythonHelpers::newref( pyobject_cast( first ) );
+	term->variable = cppy::incref( pyobject_cast( first ) );
 	term->coefficient = second;
 	return pyterm;
 }
@@ -103,11 +101,11 @@ PyObject* BinaryMul::operator()( Variable* first, double second )
 template<> inline
 PyObject* BinaryMul::operator()( Term* first, double second )
 {
-	PyObject* pyterm = PyType_GenericNew( &Term_Type, 0, 0 );
+	PyObject* pyterm = PyType_GenericNew( Term::TypeObject, 0, 0 );
 	if( !pyterm )
 		return 0;
 	Term* term = reinterpret_cast<Term*>( pyterm );
-	term->variable = PythonHelpers::newref( first->variable );
+	term->variable = cppy::incref( first->variable );
 	term->coefficient = first->coefficient * second;
 	return pyterm;
 }
@@ -116,12 +114,11 @@ PyObject* BinaryMul::operator()( Term* first, double second )
 template<> inline
 PyObject* BinaryMul::operator()( Expression* first, double second )
 {
-	using namespace PythonHelpers;
-	PyObjectPtr pyexpr( PyType_GenericNew( &Expression_Type, 0, 0 ) );
+	cppy::ptr pyexpr( PyType_GenericNew( Expression::TypeObject, 0, 0 ) );
 	if( !pyexpr )
 		return 0;
 	Expression* expr = reinterpret_cast<Expression*>( pyexpr.get() );
-	PyObjectPtr terms( PyTuple_New( PyTuple_GET_SIZE( first->terms ) ) );
+	cppy::ptr terms( PyTuple_New( PyTuple_GET_SIZE( first->terms ) ) );
 	if( !terms )
 		return 0;
 	Py_ssize_t end = PyTuple_GET_SIZE( first->terms );
@@ -252,7 +249,7 @@ struct BinaryAdd
 template<> inline
 PyObject* BinaryAdd::operator()( Expression* first, Expression* second )
 {
-	PythonHelpers::PyObjectPtr pyexpr( PyType_GenericNew( &Expression_Type, 0, 0 ) );
+	cppy::ptr pyexpr( PyType_GenericNew( Expression::TypeObject, 0, 0 ) );
 	if( !pyexpr )
 		return 0;
 	Expression* expr = reinterpret_cast<Expression*>( pyexpr.get() );
@@ -267,8 +264,7 @@ PyObject* BinaryAdd::operator()( Expression* first, Expression* second )
 template<> inline
 PyObject* BinaryAdd::operator()( Expression* first, Term* second )
 {
-	using namespace PythonHelpers;
-	PyObjectPtr pyexpr( PyType_GenericNew( &Expression_Type, 0, 0 ) );
+	cppy::ptr pyexpr( PyType_GenericNew( Expression::TypeObject, 0, 0 ) );
 	if( !pyexpr )
 		return 0;
 	PyObject* terms = PyTuple_New( PyTuple_GET_SIZE( first->terms ) + 1 );
@@ -278,9 +274,9 @@ PyObject* BinaryAdd::operator()( Expression* first, Term* second )
 	for( Py_ssize_t i = 0; i < end; ++i )
 	{
 		PyObject* item = PyTuple_GET_ITEM( first->terms, i );
-		PyTuple_SET_ITEM( terms, i, newref( item ) );
+		PyTuple_SET_ITEM( terms, i, cppy::incref( item ) );
 	}
-	PyTuple_SET_ITEM( terms, end, newref( pyobject_cast( second ) ) );
+	PyTuple_SET_ITEM( terms, end, cppy::incref( pyobject_cast( second ) ) );
 	Expression* expr = reinterpret_cast<Expression*>( pyexpr.get() );
 	expr->terms = terms;
 	expr->constant = first->constant;
@@ -291,7 +287,7 @@ PyObject* BinaryAdd::operator()( Expression* first, Term* second )
 template<> inline
 PyObject* BinaryAdd::operator()( Expression* first, Variable* second )
 {
-	PythonHelpers::PyObjectPtr temp( BinaryMul()( second, 1.0 ) );
+	cppy::ptr temp( BinaryMul()( second, 1.0 ) );
 	if( !temp )
 		return 0;
 	return operator()( first, reinterpret_cast<Term*>( temp.get() ) );
@@ -301,12 +297,11 @@ PyObject* BinaryAdd::operator()( Expression* first, Variable* second )
 template<> inline
 PyObject* BinaryAdd::operator()( Expression* first, double second )
 {
-	using namespace PythonHelpers;
-	PyObjectPtr pyexpr( PyType_GenericNew( &Expression_Type, 0, 0 ) );
+	cppy::ptr pyexpr( PyType_GenericNew( Expression::TypeObject, 0, 0 ) );
 	if( !pyexpr )
 		return 0;
 	Expression* expr = reinterpret_cast<Expression*>( pyexpr.get() );
-	expr->terms = newref( first->terms );
+	expr->terms = cppy::incref( first->terms );
 	expr->constant = first->constant + second;
 	return pyexpr.release();
 }
@@ -315,7 +310,7 @@ PyObject* BinaryAdd::operator()( Expression* first, double second )
 template<> inline
 PyObject* BinaryAdd::operator()( Term* first, double second )
 {
-	PythonHelpers::PyObjectPtr pyexpr( PyType_GenericNew( &Expression_Type, 0, 0 ) );
+	cppy::ptr pyexpr( PyType_GenericNew( Expression::TypeObject, 0, 0 ) );
 	if( !pyexpr )
 		return 0;
 	Expression* expr = reinterpret_cast<Expression*>( pyexpr.get() );
@@ -337,7 +332,7 @@ PyObject* BinaryAdd::operator()( Term* first, Expression* second )
 template<> inline
 PyObject* BinaryAdd::operator()( Term* first, Term* second )
 {
-	PythonHelpers::PyObjectPtr pyexpr( PyType_GenericNew( &Expression_Type, 0, 0 ) );
+	cppy::ptr pyexpr( PyType_GenericNew( Expression::TypeObject, 0, 0 ) );
 	if( !pyexpr )
 		return 0;
 	Expression* expr = reinterpret_cast<Expression*>( pyexpr.get() );
@@ -352,7 +347,7 @@ PyObject* BinaryAdd::operator()( Term* first, Term* second )
 template<> inline
 PyObject* BinaryAdd::operator()( Term* first, Variable* second )
 {
-	PythonHelpers::PyObjectPtr temp( BinaryMul()( second, 1.0 ) );
+	cppy::ptr temp( BinaryMul()( second, 1.0 ) );
 	if( !temp )
 		return 0;
 	return BinaryAdd()( first, reinterpret_cast<Term*>( temp.get() ) );
@@ -362,7 +357,7 @@ PyObject* BinaryAdd::operator()( Term* first, Variable* second )
 template<> inline
 PyObject* BinaryAdd::operator()( Variable* first, double second )
 {
-	PythonHelpers::PyObjectPtr temp( BinaryMul()( first, 1.0 ) );
+	cppy::ptr temp( BinaryMul()( first, 1.0 ) );
 	if( !temp )
 		return 0;
 	return operator()( reinterpret_cast<Term*>( temp.get() ), second );
@@ -372,7 +367,7 @@ PyObject* BinaryAdd::operator()( Variable* first, double second )
 template<> inline
 PyObject* BinaryAdd::operator()( Variable* first, Variable* second )
 {
-	PythonHelpers::PyObjectPtr temp( BinaryMul()( first, 1.0 ) );
+	cppy::ptr temp( BinaryMul()( first, 1.0 ) );
 	if( !temp )
 		return 0;
 	return operator()( reinterpret_cast<Term*>( temp.get() ), second );
@@ -382,7 +377,7 @@ PyObject* BinaryAdd::operator()( Variable* first, Variable* second )
 template<> inline
 PyObject* BinaryAdd::operator()( Variable* first, Term* second )
 {
-	PythonHelpers::PyObjectPtr temp( BinaryMul()( first, 1.0 ) );
+	cppy::ptr temp( BinaryMul()( first, 1.0 ) );
 	if( !temp )
 		return 0;
 	return operator()( reinterpret_cast<Term*>( temp.get() ), second );
@@ -392,7 +387,7 @@ PyObject* BinaryAdd::operator()( Variable* first, Term* second )
 template<> inline
 PyObject* BinaryAdd::operator()( Variable* first, Expression* second )
 {
-	PythonHelpers::PyObjectPtr temp( BinaryMul()( first, 1.0 ) );
+	cppy::ptr temp( BinaryMul()( first, 1.0 ) );
 	if( !temp )
 		return 0;
 	return operator()( reinterpret_cast<Term*>( temp.get() ), second );
@@ -440,7 +435,7 @@ PyObject* BinarySub::operator()( Variable* first, double second )
 template<> inline
 PyObject* BinarySub::operator()( Variable* first, Variable* second )
 {
-	PythonHelpers::PyObjectPtr temp( UnaryNeg()( second ) );
+	cppy::ptr temp( UnaryNeg()( second ) );
 	if( !temp )
 		return 0;
 	return BinaryAdd()( first, reinterpret_cast<Term*>( temp.get() ) );
@@ -450,7 +445,7 @@ PyObject* BinarySub::operator()( Variable* first, Variable* second )
 template<> inline
 PyObject* BinarySub::operator()( Variable* first, Term* second )
 {
-	PythonHelpers::PyObjectPtr temp( UnaryNeg()( second ) );
+	cppy::ptr temp( UnaryNeg()( second ) );
 	if( !temp )
 		return 0;
 	return BinaryAdd()( first, reinterpret_cast<Term*>( temp.get() ) );
@@ -460,7 +455,7 @@ PyObject* BinarySub::operator()( Variable* first, Term* second )
 template<> inline
 PyObject* BinarySub::operator()( Variable* first, Expression* second )
 {
-	PythonHelpers::PyObjectPtr temp( UnaryNeg()( second ) );
+	cppy::ptr temp( UnaryNeg()( second ) );
 	if( !temp )
 		return 0;
 	return BinaryAdd()( first, reinterpret_cast<Expression*>( temp.get() ) );
@@ -477,7 +472,7 @@ PyObject* BinarySub::operator()( Term* first, double second )
 template<> inline
 PyObject* BinarySub::operator()( Term* first, Variable* second )
 {
-	PythonHelpers::PyObjectPtr temp( UnaryNeg()( second ) );
+	cppy::ptr temp( UnaryNeg()( second ) );
 	if( !temp )
 		return 0;
 	return BinaryAdd()( first, reinterpret_cast<Term*>( temp.get() ) );
@@ -487,7 +482,7 @@ PyObject* BinarySub::operator()( Term* first, Variable* second )
 template<> inline
 PyObject* BinarySub::operator()( Term* first, Term* second )
 {
-	PythonHelpers::PyObjectPtr temp( UnaryNeg()( second ) );
+	cppy::ptr temp( UnaryNeg()( second ) );
 	if( !temp )
 		return 0;
 	return BinaryAdd()( first, reinterpret_cast<Term*>( temp.get() ) );
@@ -497,7 +492,7 @@ PyObject* BinarySub::operator()( Term* first, Term* second )
 template<> inline
 PyObject* BinarySub::operator()( Term* first, Expression* second )
 {
-	PythonHelpers::PyObjectPtr temp( UnaryNeg()( second ) );
+	cppy::ptr temp( UnaryNeg()( second ) );
 	if( !temp )
 		return 0;
 	return BinaryAdd()( first, reinterpret_cast<Expression*>( temp.get() ) );
@@ -514,7 +509,7 @@ PyObject* BinarySub::operator()( Expression* first, double second )
 template<> inline
 PyObject* BinarySub::operator()( Expression* first, Variable* second )
 {
-	PythonHelpers::PyObjectPtr temp( UnaryNeg()( second ) );
+	cppy::ptr temp( UnaryNeg()( second ) );
 	if( !temp )
 		return 0;
 	return BinaryAdd()( first, reinterpret_cast<Term*>( temp.get() ) );
@@ -524,7 +519,7 @@ PyObject* BinarySub::operator()( Expression* first, Variable* second )
 template<> inline
 PyObject* BinarySub::operator()( Expression* first, Term* second )
 {
-	PythonHelpers::PyObjectPtr temp( UnaryNeg()( second ) );
+	cppy::ptr temp( UnaryNeg()( second ) );
 	if( !temp )
 		return 0;
 	return BinaryAdd()( first, reinterpret_cast<Term*>( temp.get() ) );
@@ -534,7 +529,7 @@ PyObject* BinarySub::operator()( Expression* first, Term* second )
 template<> inline
 PyObject* BinarySub::operator()( Expression* first, Expression* second )
 {
-	PythonHelpers::PyObjectPtr temp( UnaryNeg()( second ) );
+	cppy::ptr temp( UnaryNeg()( second ) );
 	if( !temp )
 		return 0;
 	return BinaryAdd()( first, reinterpret_cast<Expression*>( temp.get() ) );
@@ -544,7 +539,7 @@ PyObject* BinarySub::operator()( Expression* first, Expression* second )
 template<> inline
 PyObject* BinarySub::operator()( double first, Variable* second )
 {
-	PythonHelpers::PyObjectPtr temp( UnaryNeg()( second ) );
+	cppy::ptr temp( UnaryNeg()( second ) );
 	if( !temp )
 		return 0;
 	return BinaryAdd()( first, reinterpret_cast<Term*>( temp.get() ) );
@@ -554,7 +549,7 @@ PyObject* BinarySub::operator()( double first, Variable* second )
 template<> inline
 PyObject* BinarySub::operator()( double first, Term* second )
 {
-	PythonHelpers::PyObjectPtr temp( UnaryNeg()( second ) );
+	cppy::ptr temp( UnaryNeg()( second ) );
 	if( !temp )
 		return 0;
 	return BinaryAdd()( first, reinterpret_cast<Term*>( temp.get() ) );
@@ -564,7 +559,7 @@ PyObject* BinarySub::operator()( double first, Term* second )
 template<> inline
 PyObject* BinarySub::operator()( double first, Expression* second )
 {
-	PythonHelpers::PyObjectPtr temp( UnaryNeg()( second ) );
+	cppy::ptr temp( UnaryNeg()( second ) );
 	if( !temp )
 		return 0;
 	return BinaryAdd()( first, reinterpret_cast<Expression*>( temp.get() ) );
@@ -574,10 +569,10 @@ PyObject* BinarySub::operator()( double first, Expression* second )
 template<typename T, typename U>
 PyObject* makecn( T first, U second, kiwi::RelationalOperator op )
 {
-	PythonHelpers::PyObjectPtr pyexpr( BinarySub()( first, second ) );
+	cppy::ptr pyexpr( BinarySub()( first, second ) );
 	if( !pyexpr )
 		return 0;
-	PythonHelpers::PyObjectPtr pycn( PyType_GenericNew( &Constraint_Type, 0, 0 ) );
+	cppy::ptr pycn( PyType_GenericNew( Constraint::TypeObject, 0, 0 ) );
 	if( !pycn )
 		return 0;
 	Constraint* cn = reinterpret_cast<Constraint*>( pycn.get() );
@@ -618,3 +613,6 @@ struct CmpGE
 		return makecn( first, second, kiwi::OP_GE );
 	}
 };
+
+
+}  // namespace kiwisolver
diff --git a/contrib/python/kiwisolver/py3/py/term.cpp b/contrib/python/kiwisolver/py3/py/term.cpp
index 4be64a1eeaf..923e0cf8582 100644
--- a/contrib/python/kiwisolver/py3/py/term.cpp
+++ b/contrib/python/kiwisolver/py3/py/term.cpp
@@ -1,22 +1,26 @@
 /*-----------------------------------------------------------------------------
-| Copyright (c) 2013-2017, Nucleic Development Team.
+| Copyright (c) 2013-2019, Nucleic Development Team.
 |
 | Distributed under the terms of the Modified BSD License.
 |
-| The full license is in the file COPYING.txt, distributed with this software.
+| The full license is in the file LICENSE, distributed with this software.
 |----------------------------------------------------------------------------*/
 #include <sstream>
-#include <Python.h>
-#include "pythonhelpers.h"
+#include <cppy/cppy.h>
 #include "symbolics.h"
 #include "types.h"
 #include "util.h"
 
 
-using namespace PythonHelpers;
+namespace kiwisolver
+{
+
 
+namespace
+{
 
-static PyObject*
+
+PyObject*
 Term_new( PyTypeObject* type, PyObject* args, PyObject* kwargs )
 {
 	static const char *kwlist[] = { "variable", "coefficient", 0 };
@@ -27,7 +31,7 @@ Term_new( PyTypeObject* type, PyObject* args, PyObject* kwargs )
 		&pyvar, &pycoeff ) )
 		return 0;
 	if( !Variable::TypeCheck( pyvar ) )
-		return py_expected_type_fail( pyvar, "Variable" );
+		return cppy::type_error( pyvar, "Variable" );
 	double coefficient = 1.0;
 	if( pycoeff && !convert_to_double( pycoeff, coefficient ) )
 		return 0;
@@ -35,20 +39,20 @@ Term_new( PyTypeObject* type, PyObject* args, PyObject* kwargs )
 	if( !pyterm )
 		return 0;
 	Term* self = reinterpret_cast<Term*>( pyterm );
-	self->variable = newref( pyvar );
+	self->variable = cppy::incref( pyvar );
 	self->coefficient = coefficient;
 	return pyterm;
 }
 
 
-static void
+void
 Term_clear( Term* self )
 {
 	Py_CLEAR( self->variable );
 }
 
 
-static int
+int
 Term_traverse( Term* self, visitproc visit, void* arg )
 {
 	Py_VISIT( self->variable );
@@ -56,7 +60,7 @@ Term_traverse( Term* self, visitproc visit, void* arg )
 }
 
 
-static void
+void
 Term_dealloc( Term* self )
 {
 	PyObject_GC_UnTrack( self );
@@ -65,31 +69,31 @@ Term_dealloc( Term* self )
 }
 
 
-static PyObject*
+PyObject*
 Term_repr( Term* self )
 {
 	std::stringstream stream;
 	stream << self->coefficient << " * ";
 	stream << reinterpret_cast<Variable*>( self->variable )->variable.name();
-	return FROM_STRING( stream.str().c_str() );
+	return PyUnicode_FromString( stream.str().c_str() );
 }
 
 
-static PyObject*
+PyObject*
 Term_variable( Term* self )
 {
-	return newref( self->variable );
+	return cppy::incref( self->variable );
 }
 
 
-static PyObject*
+PyObject*
 Term_coefficient( Term* self )
 {
 	return PyFloat_FromDouble( self->coefficient );
 }
 
 
-static PyObject*
+PyObject*
 Term_value( Term* self )
 {
 	Variable* pyvar = reinterpret_cast<Variable*>( self->variable );
@@ -97,42 +101,42 @@ Term_value( Term* self )
 }
 
 
-static PyObject*
+PyObject*
 Term_add( PyObject* first, PyObject* second )
 {
 	return BinaryInvoke<BinaryAdd, Term>()( first, second );
 }
 
 
-static PyObject*
+PyObject*
 Term_sub( PyObject* first, PyObject* second )
 {
 	return BinaryInvoke<BinarySub, Term>()( first, second );
 }
 
 
-static PyObject*
+PyObject*
 Term_mul( PyObject* first, PyObject* second )
 {
 	return BinaryInvoke<BinaryMul, Term>()( first, second );
 }
 
 
-static PyObject*
+PyObject*
 Term_div( PyObject* first, PyObject* second )
 {
 	return BinaryInvoke<BinaryDiv, Term>()( first, second );
 }
 
 
-static PyObject*
+PyObject*
 Term_neg( PyObject* value )
 {
 	return UnaryInvoke<UnaryNeg, Term>()( value );
 }
 
 
-static PyObject*
+PyObject*
 Term_richcmp( PyObject* first, PyObject* second, int op )
 {
 	switch( op )
@@ -170,129 +174,52 @@ Term_methods[] = {
 };
 
 
-static PyNumberMethods
-Term_as_number = {
-	(binaryfunc)Term_add,       /* nb_add */
-	(binaryfunc)Term_sub,       /* nb_subtract */
-	(binaryfunc)Term_mul,       /* nb_multiply */
-#if PY_MAJOR_VERSION < 3
-	(binaryfunc)Term_div,       /* nb_divide */
-#endif
-	0,                          /* nb_remainder */
-	0,                          /* nb_divmod */
-	0,                          /* nb_power */
-	(unaryfunc)Term_neg,        /* nb_negative */
-	0,                          /* nb_positive */
-	0,                          /* nb_absolute */
-#if PY_MAJOR_VERSION >= 3
-	0,                          /* nb_bool */
-#else
-	0,                          /* nb_nonzero */
-#endif
-	0,                          /* nb_invert */
-	0,                          /* nb_lshift */
-	0,                          /* nb_rshift */
-	0,                          /* nb_and */
-	0,                          /* nb_xor */
-	(binaryfunc)0,              /* nb_or */
-#if PY_MAJOR_VERSION < 3
-	0,                          /* nb_coerce */
-#endif
-	0,                          /* nb_int */
-	0,                          /* nb_long */
-	0,                          /* nb_float */
-#if PY_MAJOR_VERSION < 3
-	0,                          /* nb_oct */
-	0,                          /* nb_hex */
-#endif
-	0,                          /* nb_inplace_add */
-	0,                          /* nb_inplace_subtract */
-	0,                          /* nb_inplace_multiply */
-#if PY_MAJOR_VERSION < 3
-	0,                          /* nb_inplace_divide */
-#endif
-	0,                          /* nb_inplace_remainder */
-	0,                          /* nb_inplace_power */
-	0,                          /* nb_inplace_lshift */
-	0,                          /* nb_inplace_rshift */
-	0,                          /* nb_inplace_and */
-	0,                          /* nb_inplace_xor */
-	0,                          /* nb_inplace_or */
-	(binaryfunc)0,              /* nb_floor_divide */
-	(binaryfunc)Term_div,       /* nb_true_divide */
-	0,                          /* nb_inplace_floor_divide */
-	0,                          /* nb_inplace_true_divide */
-#if PY_VERSION_HEX >= 0x02050000
-	(unaryfunc)0,               /* nb_index */
-#endif
-#if PY_VERSION_HEX >= 0x03050000
-	(binaryfunc)0,              /* nb_matrix_multiply */
-	(binaryfunc)0,              /* nb_inplace_matrix_multiply */
-#endif
+static PyType_Slot Term_Type_slots[] = {
+    { Py_tp_dealloc, void_cast( Term_dealloc ) },      /* tp_dealloc */
+    { Py_tp_traverse, void_cast( Term_traverse ) },    /* tp_traverse */
+    { Py_tp_clear, void_cast( Term_clear ) },          /* tp_clear */
+    { Py_tp_repr, void_cast( Term_repr ) },            /* tp_repr */
+    { Py_tp_richcompare, void_cast( Term_richcmp ) },  /* tp_richcompare */
+    { Py_tp_methods, void_cast( Term_methods ) },      /* tp_methods */
+    { Py_tp_new, void_cast( Term_new ) },              /* tp_new */
+    { Py_tp_alloc, void_cast( PyType_GenericAlloc ) }, /* tp_alloc */
+    { Py_tp_free, void_cast( PyObject_GC_Del ) },      /* tp_free */
+    { Py_nb_add, void_cast( Term_add ) },              /* nb_add */
+    { Py_nb_subtract, void_cast( Term_sub ) },         /* nb_subatract */
+    { Py_nb_multiply, void_cast( Term_mul ) },         /* nb_multiply */
+    { Py_nb_negative, void_cast( Term_neg ) },         /* nb_negative */
+    { Py_nb_true_divide, void_cast( Term_div ) },      /* nb_true_divide */
+    { 0, 0 },
 };
 
 
-PyTypeObject Term_Type = {
-	PyVarObject_HEAD_INIT( &PyType_Type, 0 )
-	"kiwisolver.Term",                      /* tp_name */
-	sizeof( Term ),                         /* tp_basicsize */
-	0,                                      /* tp_itemsize */
-	(destructor)Term_dealloc,               /* tp_dealloc */
-	(printfunc)0,                           /* tp_print */
-	(getattrfunc)0,                         /* tp_getattr */
-	(setattrfunc)0,                         /* tp_setattr */
-#if PY_VERSION_HEX >= 0x03050000
-	( PyAsyncMethods* )0,                   /* tp_as_async */
-#elif PY_VERSION_HEX >= 0x03000000
-	( void* ) 0,                            /* tp_reserved */
-#else
-	( cmpfunc )0,                           /* tp_compare */
-#endif
-	(reprfunc)Term_repr,                    /* tp_repr */
-	(PyNumberMethods*)&Term_as_number,      /* tp_as_number */
-	(PySequenceMethods*)0,                  /* tp_as_sequence */
-	(PyMappingMethods*)0,                   /* tp_as_mapping */
-	(hashfunc)0,                            /* tp_hash */
-	(ternaryfunc)0,                         /* tp_call */
-	(reprfunc)0,                            /* tp_str */
-	(getattrofunc)0,                        /* tp_getattro */
-	(setattrofunc)0,                        /* tp_setattro */
-	(PyBufferProcs*)0,                      /* tp_as_buffer */
-#if PY_MAJOR_VERSION >= 3
-	Py_TPFLAGS_DEFAULT|Py_TPFLAGS_HAVE_GC|Py_TPFLAGS_BASETYPE, /* tp_flags */
-#else
-	Py_TPFLAGS_DEFAULT|Py_TPFLAGS_HAVE_GC|Py_TPFLAGS_BASETYPE|Py_TPFLAGS_CHECKTYPES, /* tp_flags */
-#endif
-	0,                                      /* Documentation string */
-	(traverseproc)Term_traverse,            /* tp_traverse */
-	(inquiry)Term_clear,                    /* tp_clear */
-	(richcmpfunc)Term_richcmp,              /* tp_richcompare */
-	0,                                      /* tp_weaklistoffset */
-	(getiterfunc)0,                         /* tp_iter */
-	(iternextfunc)0,                        /* tp_iternext */
-	(struct PyMethodDef*)Term_methods,      /* tp_methods */
-	(struct PyMemberDef*)0,                 /* tp_members */
-	0,                                      /* tp_getset */
-	0,                                      /* tp_base */
-	0,                                      /* tp_dict */
-	(descrgetfunc)0,                        /* tp_descr_get */
-	(descrsetfunc)0,                        /* tp_descr_set */
-	0,                                      /* tp_dictoffset */
-	(initproc)0,                            /* tp_init */
-	(allocfunc)PyType_GenericAlloc,         /* tp_alloc */
-	(newfunc)Term_new,                      /* tp_new */
-	(freefunc)PyObject_GC_Del,              /* tp_free */
-	(inquiry)0,                             /* tp_is_gc */
-	0,                                      /* tp_bases */
-	0,                                      /* tp_mro */
-	0,                                      /* tp_cache */
-	0,                                      /* tp_subclasses */
-	0,                                      /* tp_weaklist */
-	(destructor)0                           /* tp_del */
+} // namespace
+
+
+// Initialize static variables (otherwise the compiler eliminates them)
+PyTypeObject* Term::TypeObject = NULL;
+
+
+PyType_Spec Term::TypeObject_Spec = {
+	"kiwisolver.Term",             /* tp_name */
+	sizeof( Term ),                /* tp_basicsize */
+	0,                                   /* tp_itemsize */
+	Py_TPFLAGS_DEFAULT|
+    Py_TPFLAGS_HAVE_GC|
+    Py_TPFLAGS_BASETYPE,                 /* tp_flags */
+    Term_Type_slots                /* slots */
 };
 
 
-int import_term()
+bool Term::Ready()
 {
-	return PyType_Ready( &Term_Type );
+    // The reference will be handled by the module to which we will add the type
+	TypeObject = pytype_cast( PyType_FromSpec( &TypeObject_Spec ) );
+    if( !TypeObject )
+    {
+        return false;
+    }
+    return true;
 }
+
+}  // namespace kiwisolver
diff --git a/contrib/python/kiwisolver/py3/py/types.h b/contrib/python/kiwisolver/py3/py/types.h
index 628efafbca4..afd5b8d79e4 100644
--- a/contrib/python/kiwisolver/py3/py/types.h
+++ b/contrib/python/kiwisolver/py3/py/types.h
@@ -1,39 +1,17 @@
 /*-----------------------------------------------------------------------------
-| Copyright (c) 2013-2017, Nucleic Development Team.
+| Copyright (c) 2013-2019, Nucleic Development Team.
 |
 | Distributed under the terms of the Modified BSD License.
 |
-| The full license is in the file COPYING.txt, distributed with this software.
+| The full license is in the file LICENSE, distributed with this software.
 |----------------------------------------------------------------------------*/
 #pragma once
 #include <Python.h>
 #include <kiwi/kiwi.h>
 
 
-int import_variable();
-
-int import_term();
-
-int import_expression();
-
-int import_constraint();
-
-int import_solver();
-
-int import_strength();
-
-
-extern PyTypeObject Variable_Type;
-
-extern PyTypeObject Term_Type;
-
-extern PyTypeObject Expression_Type;
-
-extern PyTypeObject Constraint_Type;
-
-extern PyTypeObject Solver_Type;
-
-extern PyTypeObject strength_Type;
+namespace kiwisolver
+{
 
 extern PyObject* DuplicateConstraint;
 
@@ -48,15 +26,33 @@ extern PyObject* UnknownEditVariable;
 extern PyObject* BadRequiredStrength;
 
 
+struct strength
+{
+	PyObject_HEAD;
+
+    static PyType_Spec TypeObject_Spec;
+
+    static PyTypeObject* TypeObject;
+
+	static bool Ready();
+};
+
+
 struct Variable
 {
 	PyObject_HEAD
 	PyObject* context;
 	kiwi::Variable variable;
 
+    static PyType_Spec TypeObject_Spec;
+
+    static PyTypeObject* TypeObject;
+
+	static bool Ready();
+
 	static bool TypeCheck( PyObject* obj )
 	{
-		return PyObject_TypeCheck( obj, &Variable_Type ) != 0;
+		return PyObject_TypeCheck( obj, TypeObject ) != 0;
 	}
 };
 
@@ -67,9 +63,15 @@ struct Term
 	PyObject* variable;
 	double coefficient;
 
+    static PyType_Spec TypeObject_Spec;
+
+    static PyTypeObject* TypeObject;
+
+	static bool Ready();
+
 	static bool TypeCheck( PyObject* obj )
 	{
-		return PyObject_TypeCheck( obj, &Term_Type ) != 0;
+		return PyObject_TypeCheck( obj, TypeObject ) != 0;
 	}
 };
 
@@ -80,9 +82,15 @@ struct Expression
 	PyObject* terms;
 	double constant;
 
+    static PyType_Spec TypeObject_Spec;
+
+    static PyTypeObject* TypeObject;
+
+	static bool Ready();
+
 	static bool TypeCheck( PyObject* obj )
 	{
-		return PyObject_TypeCheck( obj, &Expression_Type ) != 0;
+		return PyObject_TypeCheck( obj, TypeObject ) != 0;
 	}
 };
 
@@ -93,9 +101,15 @@ struct Constraint
 	PyObject* expression;
 	kiwi::Constraint constraint;
 
+    static PyType_Spec TypeObject_Spec;
+
+    static PyTypeObject* TypeObject;
+
+	static bool Ready();
+
 	static bool TypeCheck( PyObject* obj )
 	{
-		return PyObject_TypeCheck( obj, &Constraint_Type ) != 0;
+		return PyObject_TypeCheck( obj, TypeObject ) != 0;
 	}
 };
 
@@ -105,8 +119,20 @@ struct Solver
 	PyObject_HEAD
 	kiwi::Solver solver;
 
+    static PyType_Spec TypeObject_Spec;
+
+    static PyTypeObject* TypeObject;
+
+	static bool Ready();
+
 	static bool TypeCheck( PyObject* obj )
 	{
-		return PyObject_TypeCheck( obj, &Solver_Type ) != 0;
+		return PyObject_TypeCheck( obj, TypeObject ) != 0;
 	}
 };
+
+
+bool init_exceptions();
+
+
+}  // namespace kiwisolver
diff --git a/contrib/python/kiwisolver/py3/py/util.h b/contrib/python/kiwisolver/py3/py/util.h
index 78e9cbd0b8e..4b00fa76e60 100644
--- a/contrib/python/kiwisolver/py3/py/util.h
+++ b/contrib/python/kiwisolver/py3/py/util.h
@@ -1,19 +1,21 @@
 /*-----------------------------------------------------------------------------
-| Copyright (c) 2013-2017, Nucleic Development Team.
+| Copyright (c) 2013-2019, Nucleic Development Team.
 |
 | Distributed under the terms of the Modified BSD License.
 |
-| The full license is in the file COPYING.txt, distributed with this software.
+| The full license is in the file LICENSE, distributed with this software.
 |----------------------------------------------------------------------------*/
 #pragma once
 #include <map>
 #include <string>
-#include <Python.h>
+#include <cppy/cppy.h>
 #include <kiwi/kiwi.h>
-#include "pythonhelpers.h"
 #include "types.h"
 
 
+namespace kiwisolver
+{
+
 inline bool
 convert_to_double( PyObject* obj, double& out )
 {
@@ -22,13 +24,6 @@ convert_to_double( PyObject* obj, double& out )
         out = PyFloat_AS_DOUBLE( obj );
         return true;
     }
-#if PY_MAJOR_VERSION < 3
-    if( PyInt_Check( obj ) )
-    {
-        out = double( PyInt_AsLong( obj ) );
-        return true;
-    }
-#endif
     if( PyLong_Check( obj ) )
     {
         out = PyLong_AsDouble( obj );
@@ -36,7 +31,7 @@ convert_to_double( PyObject* obj, double& out )
             return false;
         return true;
     }
-    PythonHelpers::py_expected_type_fail( obj, "float, int, or long" );
+    cppy::type_error( obj, "float, int, or long" );
     return false;
 }
 
@@ -44,19 +39,7 @@ convert_to_double( PyObject* obj, double& out )
 inline bool
 convert_pystr_to_str( PyObject* value, std::string& out )
 {
-#if PY_MAJOR_VERSION >= 3
     out = PyUnicode_AsUTF8( value );
-#else
-    if( PyUnicode_Check( value ) )
-    {
-        PythonHelpers::PyObjectPtr py_str( PyUnicode_AsUTF8String( value ) );
-        if( !py_str )
-             return false;  // LCOV_EXCL_LINE
-        out = PyString_AS_STRING( py_str.get() );
-    }
-    else
-        out = PyString_AS_STRING( value );
-#endif
     return true;
 }
 
@@ -64,13 +47,8 @@ convert_pystr_to_str( PyObject* value, std::string& out )
 inline bool
 convert_to_strength( PyObject* value, double& out )
 {
-#if PY_MAJOR_VERSION >= 3
     if( PyUnicode_Check( value ) )
     {
-#else
-    if( PyString_Check( value ) | PyUnicode_Check( value ))
-    {
-#endif
         std::string str;
         if( !convert_pystr_to_str( value, str ) )
             return false;
@@ -103,19 +81,11 @@ convert_to_strength( PyObject* value, double& out )
 inline bool
 convert_to_relational_op( PyObject* value, kiwi::RelationalOperator& out )
 {
-#if PY_MAJOR_VERSION >= 3
     if( !PyUnicode_Check( value ) )
     {
-        PythonHelpers::py_expected_type_fail( value, "unicode" );
+        cppy::type_error( value, "str" );
         return false;
     }
-#else
-    if( !(PyString_Check( value ) | PyUnicode_Check( value ) ) )
-    {
-        PythonHelpers::py_expected_type_fail( value, "str or unicode" );
-        return false;
-    }
-#endif
     std::string str;
     if( !convert_pystr_to_str( value, str ) )
         return false;
@@ -142,7 +112,7 @@ inline PyObject*
 make_terms( const std::map<PyObject*, double>& coeffs )
 {
     typedef std::map<PyObject*, double>::const_iterator iter_t;
-    PythonHelpers::PyObjectPtr terms( PyTuple_New( coeffs.size() ) );
+    cppy::ptr terms( PyTuple_New( coeffs.size() ) );
     if( !terms )
         return 0;
     Py_ssize_t size = PyTuple_GET_SIZE( terms.get() );
@@ -153,11 +123,11 @@ make_terms( const std::map<PyObject*, double>& coeffs )
     iter_t end = coeffs.end();
     for( ; it != end; ++it, ++i )
     {
-        PyObject* pyterm = PyType_GenericNew( &Term_Type, 0, 0 );
+        PyObject* pyterm = PyType_GenericNew( Term::TypeObject, 0, 0 );
         if( !pyterm )
             return 0;
         Term* term = reinterpret_cast<Term*>( pyterm );
-        term->variable = PythonHelpers::newref( it->first );
+        term->variable = cppy::incref( it->first );
         term->coefficient = it->second;
         PyTuple_SET_ITEM( terms.get(), i, pyterm );
     }
@@ -177,10 +147,10 @@ reduce_expression( PyObject* pyexpr )  // pyexpr must be an Expression
         Term* term = reinterpret_cast<Term*>( item );
         coeffs[ term->variable ] += term->coefficient;
     }
-    PythonHelpers::PyObjectPtr terms( make_terms( coeffs ) );
+    cppy::ptr terms( make_terms( coeffs ) );
     if( !terms )
         return 0;
-    PyObject* pynewexpr = PyType_GenericNew( &Expression_Type, 0, 0 );
+    PyObject* pynewexpr = PyType_GenericNew( Expression::TypeObject, 0, 0 );
     if( !pynewexpr )
         return 0;
     Expression* newexpr = reinterpret_cast<Expression*>( pynewexpr );
@@ -228,3 +198,6 @@ pyop_str( int op )
             return "";
     }
 }
+
+
+}  // namespace kiwisolver
diff --git a/contrib/python/kiwisolver/py3/py/variable.cpp b/contrib/python/kiwisolver/py3/py/variable.cpp
index a622e8529ab..1a9c69f8f65 100644
--- a/contrib/python/kiwisolver/py3/py/variable.cpp
+++ b/contrib/python/kiwisolver/py3/py/variable.cpp
@@ -1,22 +1,26 @@
 /*-----------------------------------------------------------------------------
-| Copyright (c) 2013-2017, Nucleic Development Team.
+| Copyright (c) 2013-2019, Nucleic Development Team.
 |
 | Distributed under the terms of the Modified BSD License.
 |
-| The full license is in the file COPYING.txt, distributed with this software.
+| The full license is in the file LICENSE, distributed with this software.
 |----------------------------------------------------------------------------*/
-#include <Python.h>
+#include <cppy/cppy.h>
 #include <kiwi/kiwi.h>
-#include "pythonhelpers.h"
 #include "symbolics.h"
 #include "types.h"
 #include "util.h"
 
 
-using namespace PythonHelpers;
+namespace kiwisolver
+{
+
+
+namespace
+{
 
 
-static PyObject*
+PyObject*
 Variable_new( PyTypeObject* type, PyObject* args, PyObject* kwargs )
 {
 	static const char *kwlist[] = { "name", "context", 0 };
@@ -28,24 +32,17 @@ Variable_new( PyTypeObject* type, PyObject* args, PyObject* kwargs )
 		&name, &context ) )
 		return 0;
 
-	PyObjectPtr pyvar( PyType_GenericNew( type, args, kwargs ) );
+	cppy::ptr pyvar( PyType_GenericNew( type, args, kwargs ) );
 	if( !pyvar )
 		return 0;
 
 	Variable* self = reinterpret_cast<Variable*>( pyvar.get() );
-	self->context = xnewref( context );
+	self->context = cppy::xincref( context );
 
 	if( name != 0 )
 	{
-#if PY_MAJOR_VERSION >= 3
 		if( !PyUnicode_Check( name ) )
-			return py_expected_type_fail( name, "unicode" );
-#else
-		if( !( PyString_Check( name ) | PyUnicode_Check( name ) ) )
-		{
-			return py_expected_type_fail( name, "str or unicode" );
-		}
-#endif
+			return cppy::type_error( name, "str" );
 		std::string c_name;
 		if( !convert_pystr_to_str(name, c_name) )
 			return 0;  // LCOV_EXCL_LINE
@@ -60,14 +57,14 @@ Variable_new( PyTypeObject* type, PyObject* args, PyObject* kwargs )
 }
 
 
-static void
+void
 Variable_clear( Variable* self )
 {
 	Py_CLEAR( self->context );
 }
 
 
-static int
+int
 Variable_traverse( Variable* self, visitproc visit, void* arg )
 {
 	Py_VISIT( self->context );
@@ -75,7 +72,7 @@ Variable_traverse( Variable* self, visitproc visit, void* arg )
 }
 
 
-static void
+void
 Variable_dealloc( Variable* self )
 {
 	PyObject_GC_UnTrack( self );
@@ -85,32 +82,25 @@ Variable_dealloc( Variable* self )
 }
 
 
-static PyObject*
+PyObject*
 Variable_repr( Variable* self )
 {
-	return FROM_STRING( self->variable.name().c_str() );
+	return PyUnicode_FromString( self->variable.name().c_str() );
 }
 
 
-static PyObject*
+PyObject*
 Variable_name( Variable* self )
 {
-	return FROM_STRING( self->variable.name().c_str() );
+	return PyUnicode_FromString( self->variable.name().c_str() );
 }
 
 
-static PyObject*
+PyObject*
 Variable_setName( Variable* self, PyObject* pystr )
 {
-#if PY_MAJOR_VERSION >= 3
 	if( !PyUnicode_Check( pystr ) )
-		return py_expected_type_fail( pystr, "unicode" );
-#else
-   if( !(PyString_Check( pystr ) | PyUnicode_Check( pystr ) ) )
-    {
-        return py_expected_type_fail( pystr, "str or unicode" );
-    }
-#endif
+		return cppy::type_error( pystr, "str" );
    std::string str;
    if( !convert_pystr_to_str( pystr, str ) )
        return 0;
@@ -119,71 +109,71 @@ Variable_setName( Variable* self, PyObject* pystr )
 }
 
 
-static PyObject*
+PyObject*
 Variable_context( Variable* self )
 {
 	if( self->context )
-		return newref( self->context );
+		return cppy::incref( self->context );
 	Py_RETURN_NONE;
 }
 
 
-static PyObject*
+PyObject*
 Variable_setContext( Variable* self, PyObject* value )
 {
 	if( value != self->context )
 	{
 		PyObject* temp = self->context;
-		self->context = newref( value );
+		self->context = cppy::incref( value );
 		Py_XDECREF( temp );
 	}
 	Py_RETURN_NONE;
 }
 
 
-static PyObject*
+PyObject*
 Variable_value( Variable* self )
 {
 	return PyFloat_FromDouble( self->variable.value() );
 }
 
 
-static PyObject*
+PyObject*
 Variable_add( PyObject* first, PyObject* second )
 {
 	return BinaryInvoke<BinaryAdd, Variable>()( first, second );
 }
 
 
-static PyObject*
+PyObject*
 Variable_sub( PyObject* first, PyObject* second )
 {
 	return BinaryInvoke<BinarySub, Variable>()( first, second );
 }
 
 
-static PyObject*
+PyObject*
 Variable_mul( PyObject* first, PyObject* second )
 {
 	return BinaryInvoke<BinaryMul, Variable>()( first, second );
 }
 
 
-static PyObject*
+PyObject*
 Variable_div( PyObject* first, PyObject* second )
 {
 	return BinaryInvoke<BinaryDiv, Variable>()( first, second );
 }
 
 
-static PyObject*
+PyObject*
 Variable_neg( PyObject* value )
 {
 	return UnaryInvoke<UnaryNeg, Variable>()( value );
 }
 
 
-static PyObject*
+PyObject*
 Variable_richcmp( PyObject* first, PyObject* second, int op )
 {
 	switch( op )
@@ -225,129 +215,52 @@ Variable_methods[] = {
 };
 
 
-static PyNumberMethods
-Variable_as_number = {
-	(binaryfunc)Variable_add,   /* nb_add */
-	(binaryfunc)Variable_sub,   /* nb_subtract */
-	(binaryfunc)Variable_mul,   /* nb_multiply */
-#if PY_MAJOR_VERSION < 3
-	(binaryfunc)Variable_div,   /* nb_divide */
-#endif
-	0,                          /* nb_remainder */
-	0,                          /* nb_divmod */
-	0,                          /* nb_power */
-	(unaryfunc)Variable_neg,    /* nb_negative */
-	0,                          /* nb_positive */
-	0,                          /* nb_absolute */
-#if PY_MAJOR_VERSION >= 3
-	0,                          /* nb_bool */
-#else
-	0,                          /* nb_nonzero */
-#endif
-	0,                          /* nb_invert */
-	0,                          /* nb_lshift */
-	0,                          /* nb_rshift */
-	0,                          /* nb_and */
-	0,                          /* nb_xor */
-	(binaryfunc)0,              /* nb_or */
-#if PY_MAJOR_VERSION < 3
-	0,                          /* nb_coerce */
-#endif
-	0,                          /* nb_int */
-	0,                          /* nb_long */
-	0,                          /* nb_float */
-#if PY_MAJOR_VERSION < 3
-	0,                          /* nb_oct */
-	0,                          /* nb_hex */
-#endif
-	0,                          /* nb_inplace_add */
-	0,                          /* nb_inplace_subtract */
-	0,                          /* nb_inplace_multiply */
-#if PY_MAJOR_VERSION < 3
-	0,                          /* nb_inplace_divide */
-#endif
-	0,                          /* nb_inplace_remainder */
-	0,                          /* nb_inplace_power */
-	0,                          /* nb_inplace_lshift */
-	0,                          /* nb_inplace_rshift */
-	0,                          /* nb_inplace_and */
-	0,                          /* nb_inplace_xor */
-	0,                          /* nb_inplace_or */
-	(binaryfunc)0,              /* nb_floor_divide */
-	(binaryfunc)Variable_div,   /* nb_true_divide */
-	0,                          /* nb_inplace_floor_divide */
-	0,                          /* nb_inplace_true_divide */
-#if PY_VERSION_HEX >= 0x02050000
-	(unaryfunc)0,               /* nb_index */
-#endif
-#if PY_VERSION_HEX >= 0x03050000
-	(binaryfunc)0,              /* nb_matrix_multiply */
-	(binaryfunc)0,              /* nb_inplace_matrix_multiply */
-#endif
+static PyType_Slot Variable_Type_slots[] = {
+    { Py_tp_dealloc, void_cast( Variable_dealloc ) },      /* tp_dealloc */
+    { Py_tp_traverse, void_cast( Variable_traverse ) },    /* tp_traverse */
+    { Py_tp_clear, void_cast( Variable_clear ) },          /* tp_clear */
+    { Py_tp_repr, void_cast( Variable_repr ) },            /* tp_repr */
+    { Py_tp_richcompare, void_cast( Variable_richcmp ) },  /* tp_richcompare */
+    { Py_tp_methods, void_cast( Variable_methods ) },      /* tp_methods */
+    { Py_tp_new, void_cast( Variable_new ) },              /* tp_new */
+    { Py_tp_alloc, void_cast( PyType_GenericAlloc ) },     /* tp_alloc */
+    { Py_tp_free, void_cast( PyObject_GC_Del ) },          /* tp_free */
+    { Py_nb_add, void_cast( Variable_add ) },              /* nb_add */
+    { Py_nb_subtract, void_cast( Variable_sub ) },         /* nb_subtract */
+    { Py_nb_multiply, void_cast( Variable_mul ) },         /* nb_multiply */
+    { Py_nb_negative, void_cast( Variable_neg ) },         /* nb_negative */
+    { Py_nb_true_divide, void_cast( Variable_div ) },      /* nb_true_divide */
+    { 0, 0 },
 };
 
 
-PyTypeObject Variable_Type = {
-	PyVarObject_HEAD_INIT( &PyType_Type, 0 )
-	"kiwisolver.Variable",                  /* tp_name */
-	sizeof( Variable ),                     /* tp_basicsize */
-	0,                                      /* tp_itemsize */
-	(destructor)Variable_dealloc,           /* tp_dealloc */
-	(printfunc)0,                           /* tp_print */
-	(getattrfunc)0,                         /* tp_getattr */
-	(setattrfunc)0,                         /* tp_setattr */
-#if PY_VERSION_HEX >= 0x03050000
-	( PyAsyncMethods* )0,                   /* tp_as_async */
-#elif PY_VERSION_HEX >= 0x03000000
-	( void* ) 0,                            /* tp_reserved */
-#else
-	( cmpfunc )0,                           /* tp_compare */
-#endif
-	(reprfunc)Variable_repr,                /* tp_repr */
-	(PyNumberMethods*)&Variable_as_number,  /* tp_as_number */
-	(PySequenceMethods*)0,                  /* tp_as_sequence */
-	(PyMappingMethods*)0,                   /* tp_as_mapping */
-	(hashfunc)0,                            /* tp_hash */
-	(ternaryfunc)0,                         /* tp_call */
-	(reprfunc)0,                            /* tp_str */
-	(getattrofunc)0,                        /* tp_getattro */
-	(setattrofunc)0,                        /* tp_setattro */
-	(PyBufferProcs*)0,                      /* tp_as_buffer */
-#if PY_MAJOR_VERSION >= 3
-	Py_TPFLAGS_DEFAULT|Py_TPFLAGS_HAVE_GC|Py_TPFLAGS_BASETYPE, /* tp_flags */
-#else
-	Py_TPFLAGS_DEFAULT|Py_TPFLAGS_HAVE_GC|Py_TPFLAGS_BASETYPE|Py_TPFLAGS_CHECKTYPES, /* tp_flags */
-#endif
-	0,                                      /* Documentation string */
-	(traverseproc)Variable_traverse,        /* tp_traverse */
-	(inquiry)Variable_clear,                /* tp_clear */
-	(richcmpfunc)Variable_richcmp,          /* tp_richcompare */
-	0,                                      /* tp_weaklistoffset */
-	(getiterfunc)0,                         /* tp_iter */
-	(iternextfunc)0,                        /* tp_iternext */
-	(struct PyMethodDef*)Variable_methods,  /* tp_methods */
-	(struct PyMemberDef*)0,                 /* tp_members */
-	0,                                      /* tp_getset */
-	0,                                      /* tp_base */
-	0,                                      /* tp_dict */
-	(descrgetfunc)0,                        /* tp_descr_get */
-	(descrsetfunc)0,                        /* tp_descr_set */
-	0,                                      /* tp_dictoffset */
-	(initproc)0,                            /* tp_init */
-	(allocfunc)PyType_GenericAlloc,         /* tp_alloc */
-	(newfunc)Variable_new,                  /* tp_new */
-	(freefunc)PyObject_GC_Del,              /* tp_free */
-	(inquiry)0,                             /* tp_is_gc */
-	0,                                      /* tp_bases */
-	0,                                      /* tp_mro */
-	0,                                      /* tp_cache */
-	0,                                      /* tp_subclasses */
-	0,                                      /* tp_weaklist */
-	(destructor)0                           /* tp_del */
+} // namespace
+
+
+// Initialize static variables (otherwise the compiler eliminates them)
+PyTypeObject* Variable::TypeObject = NULL;
+
+
+PyType_Spec Variable::TypeObject_Spec = {
+	"kiwisolver.Variable",             /* tp_name */
+	sizeof( Variable ),                /* tp_basicsize */
+	0,                                 /* tp_itemsize */
+	Py_TPFLAGS_DEFAULT|
+    Py_TPFLAGS_HAVE_GC|
+    Py_TPFLAGS_BASETYPE,               /* tp_flags */
+    Variable_Type_slots                /* slots */
 };
 
 
-int import_variable()
+bool Variable::Ready()
 {
-	return PyType_Ready( &Variable_Type );
+    // The reference will be handled by the module to which we will add the type
+	TypeObject = pytype_cast( PyType_FromSpec( &TypeObject_Spec ) );
+    if( !TypeObject )
+    {
+        return false;
+    }
+    return true;
 }
+
+}  // namespace kiwisolver