Move concepts to library/cpp/yt/misc/concepts.h

Done
b2c0a25fcacbb46fcf6294ce86b1a27ad2adac50

2 files changed, 53 insertions, 28 deletions

diff --git a/library/cpp/yt/memory/function_view.h b/library/cpp/yt/memory/function_view.h
index 259238521f..108fd076ce 100644
--- a/library/cpp/yt/memory/function_view.h
+++ b/library/cpp/yt/memory/function_view.h
@@ -1,36 +1,11 @@
 #pragma once
 
-#include <concepts>
+#include <library/cpp/yt/misc/concepts.h>
 
 namespace NYT {
 
 ////////////////////////////////////////////////////////////////////////////////
 
-namespace NDetail {
-
-template <class TSignature>
-struct TTypeErasureTraits;
-
-template <class TResult, bool NoExcept, class... TArgs>
-struct TTypeErasureTraits<TResult(TArgs...) noexcept(NoExcept)>
-{
-    using TSignature = TResult(TArgs...) noexcept(NoExcept);
-
-    // TODO(arkady-e1ppa): Support pointer-to-member-function?
-    template <class T>
-    static constexpr bool IsInvocable = NoExcept
-        ? requires (T obj, TArgs... args) {
-            { obj(std::forward<TArgs>(args)...) } noexcept -> std::same_as<TResult>;
-        }
-        : requires (T obj, TArgs... args) {
-            { obj(std::forward<TArgs>(args)...) } -> std::same_as<TResult>;
-        };
-};
-
-} // namespace NDetail
-
-////////////////////////////////////////////////////////////////////////////////
-
 // Non-owning type-erasure container.
 /*
     Example:
@@ -75,9 +50,10 @@ class TFunctionView;
 
 ////////////////////////////////////////////////////////////////////////////////
 
+// TODO(arkady-e1ppa): Support pointer-to-member-function?
 template <class T, class TSignature>
 concept CTypeErasable =
-    NDetail::TTypeErasureTraits<TSignature>::template IsInvocable<T> &&
+    CInvocable<T, TSignature> &&
     (!std::same_as<T, TFunctionView<TSignature>>);
 
 ////////////////////////////////////////////////////////////////////////////////
@@ -105,7 +81,7 @@ public:
     bool IsValid() const noexcept;
     void Reset() noexcept;
 
-    // bool operator==(const TFunctionView& other) const & = default;
+    bool operator==(const TFunctionView& other) const & = default;
 
 private:
     // NB: Technically, this is UB according to C standard, which
diff --git a/library/cpp/yt/misc/concepts.h b/library/cpp/yt/misc/concepts.h
new file mode 100644
index 0000000000..976c707ffe
--- /dev/null
+++ b/library/cpp/yt/misc/concepts.h
@@ -0,0 +1,49 @@
+#pragma once
+
+#include <concepts>
+
+namespace NYT {
+
+////////////////////////////////////////////////////////////////////////////////
+
+namespace NDetail {
+
+template <class T, class TSignature>
+struct TIsInvocable;
+
+template <class T, class TResult, bool NoExcept, class... TArgs>
+struct TIsInvocable<T, TResult(TArgs...) noexcept(NoExcept)>
+{
+private:
+    static constexpr bool IsInvocable_ = requires (T&& t, TArgs&&... args) {
+        { std::forward<T>(t)(std::forward<TArgs>(args)...) } -> std::same_as<TResult>;
+    };
+
+    static constexpr bool IsNoThrowInvocable_ = requires (T&& t, TArgs&&... args) {
+        { std::forward<T>(t)(std::forward<TArgs>(args)...) } noexcept -> std::same_as<TResult>;
+    };
+
+public:
+    static constexpr bool Value =
+        IsInvocable_ &&
+        (!NoExcept || IsNoThrowInvocable_);
+};
+
+} // namespace NDetail
+
+////////////////////////////////////////////////////////////////////////////////
+
+template <class TObject, class TScalar>
+concept CScalable = requires (TObject object, TScalar scalar)
+{
+    { object * scalar } -> std::same_as<TObject>;
+};
+
+////////////////////////////////////////////////////////////////////////////////
+
+template <class T, class TSignature>
+concept CInvocable = NDetail::TIsInvocable<T, TSignature>::Value;
+
+////////////////////////////////////////////////////////////////////////////////
+
+} // namespace NYT