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#include <util/generic/overloaded.h>
#include <library/cpp/testing/unittest/registar.h>
#include <util/generic/variant.h>
#include <util/generic/algorithm.h>
#include <tuple>
namespace {
struct TType1 {};
struct TType2 {};
struct TType3 {};
}
Y_UNIT_TEST_SUITE(TOverloadedTest) {
Y_UNIT_TEST(StaticTest) {
auto f = TOverloaded{
[](const TType1&) {},
[](const TType2&) {},
[](const TType3&) {}};
using F = decltype(f);
static_assert(std::is_invocable_v<F, TType1>);
static_assert(std::is_invocable_v<F, TType2>);
static_assert(std::is_invocable_v<F, TType3>);
static_assert(!std::is_invocable_v<F, int>);
static_assert(!std::is_invocable_v<F, double>);
}
Y_UNIT_TEST(VariantTest) {
std::variant<int, double, TType1> v = 5;
int res = 0;
std::visit(TOverloaded{
[&](int val) { res = val; },
[&](double) { res = -1; },
[&](TType1) { res = -1; }},
v);
UNIT_ASSERT_VALUES_EQUAL(res, 5);
}
Y_UNIT_TEST(TupleTest) {
std::tuple<int, double, bool, int> t{5, 3.14, true, 20};
TString res;
ForEach(t, TOverloaded{
[&](int val) { res += "(int) " + ToString(val) + ' '; },
[&](double val) { res += "(double) " + ToString(val) + ' '; },
[&](bool val) { res += "(bool) " + ToString(val) + ' '; },
});
UNIT_ASSERT_VALUES_EQUAL(res, "(int) 5 (double) 3.14 (bool) 1 (int) 20 ");
}
Y_UNIT_TEST(ImplicitConversionsTest) {
using TTestVariant = std::variant<int, double, char>;
// Purposefully exhibit inexact overload matched with implicit type
// conversions
// All cases implicitly cast to int
auto matchAsInt = [](TTestVariant var) {
return std::visit(TOverloaded{
[](int val) { return val; },
}, var);
};
UNIT_ASSERT_VALUES_EQUAL(matchAsInt(TTestVariant{17.77}), 17);
UNIT_ASSERT_VALUES_EQUAL(matchAsInt(TTestVariant{12345}), 12345);
UNIT_ASSERT_VALUES_EQUAL(matchAsInt(TTestVariant{'X'}), 88);
// All cases implicitly cast to double
auto matchAsDouble = [](TTestVariant var) {
return std::visit(TOverloaded{
[](double val) { return val; },
}, var);
};
UNIT_ASSERT_VALUES_EQUAL(matchAsDouble(TTestVariant{17.77}), 17.77);
UNIT_ASSERT_VALUES_EQUAL(matchAsDouble(TTestVariant{12345}), 12345.0);
UNIT_ASSERT_VALUES_EQUAL(matchAsDouble(TTestVariant{'X'}), 88.0);
}
}
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