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-rw-r--r--include/type_traits62
-rw-r--r--test/std/utilities/meta/meta.unary/meta.unary.prop/is_constructible.pass.cpp12
2 files changed, 70 insertions, 4 deletions
diff --git a/include/type_traits b/include/type_traits
index 7a6c992930e4..eb443ee0abd6 100644
--- a/include/type_traits
+++ b/include/type_traits
@@ -3172,6 +3172,14 @@ template <class _A0, class _A1>
false_type
__is_constructible2_test(__any, _A0&, _A1&);
+template <class _Tp, class _A0, class _A1, class _A2>
+decltype((_Tp(_VSTD::declval<_A0>(), _VSTD::declval<_A1>(), _VSTD::declval<_A2>()), true_type()))
+__is_constructible3_test(_Tp&, _A0&, _A1&, _A2&);
+
+template <class _A0, class _A1, class _A2>
+false_type
+__is_constructible3_test(__any, _A0&, _A1&, _A2&);
+
template <bool, class _Tp>
struct __is_constructible0_imp // false, _Tp is not a scalar
: public common_type
@@ -3196,6 +3204,14 @@ struct __is_constructible2_imp // false, _Tp is not a scalar
>::type
{};
+template <bool, class _Tp, class _A0, class _A1, class _A2>
+struct __is_constructible3_imp // false, _Tp is not a scalar
+ : public common_type
+ <
+ decltype(__is_constructible3_test(declval<_Tp&>(), declval<_A0>(), declval<_A1>(), declval<_A2>()))
+ >::type
+ {};
+
// handle scalars and reference types
// Scalars are default constructible, references are not
@@ -3215,6 +3231,11 @@ struct __is_constructible2_imp<true, _Tp, _A0, _A1>
: public false_type
{};
+template <class _Tp, class _A0, class _A1, class _A2>
+struct __is_constructible3_imp<true, _Tp, _A0, _A1, _A2>
+ : public false_type
+ {};
+
// Treat scalars and reference types separately
template <bool, class _Tp>
@@ -3235,6 +3256,12 @@ struct __is_constructible2_void_check
_Tp, _A0, _A1>
{};
+template <bool, class _Tp, class _A0, class _A1, class _A2>
+struct __is_constructible3_void_check
+ : public __is_constructible3_imp<is_scalar<_Tp>::value || is_reference<_Tp>::value,
+ _Tp, _A0, _A1, _A2>
+ {};
+
// If any of T or Args is void, is_constructible should be false
template <class _Tp>
@@ -3252,17 +3279,24 @@ struct __is_constructible2_void_check<true, _Tp, _A0, _A1>
: public false_type
{};
+template <class _Tp, class _A0, class _A1, class _A2>
+struct __is_constructible3_void_check<true, _Tp, _A0, _A1, _A2>
+ : public false_type
+ {};
+
// is_constructible entry point
template <class _Tp, class _A0 = __is_construct::__nat,
- class _A1 = __is_construct::__nat>
+ class _A1 = __is_construct::__nat,
+ class _A2 = __is_construct::__nat>
struct _LIBCPP_TEMPLATE_VIS is_constructible
- : public __is_constructible2_void_check<is_void<_Tp>::value
+ : public __is_constructible3_void_check<is_void<_Tp>::value
|| is_abstract<_Tp>::value
|| is_function<_Tp>::value
|| is_void<_A0>::value
- || is_void<_A1>::value,
- _Tp, _A0, _A1>
+ || is_void<_A1>::value
+ || is_void<_A2>::value,
+ _Tp, _A0, _A1, _A2>
{};
template <class _Tp>
@@ -3282,6 +3316,16 @@ struct _LIBCPP_TEMPLATE_VIS is_constructible<_Tp, _A0, __is_construct::__nat>
_Tp, _A0>
{};
+template <class _Tp, class _A0, class _A1>
+struct _LIBCPP_TEMPLATE_VIS is_constructible<_Tp, _A0, _A1, __is_construct::__nat>
+ : public __is_constructible2_void_check<is_void<_Tp>::value
+ || is_abstract<_Tp>::value
+ || is_function<_Tp>::value
+ || is_void<_A0>::value
+ || is_void<_A1>::value,
+ _Tp, _A0, _A1>
+ {};
+
// Array types are default constructible if their element type
// is default constructible
@@ -3300,6 +3344,11 @@ struct __is_constructible2_imp<false, _Ap[_Np], _A0, _A1>
: public false_type
{};
+template <class _Ap, size_t _Np, class _A0, class _A1, class _A2>
+struct __is_constructible3_imp<false, _Ap[_Np], _A0, _A1, _A2>
+ : public false_type
+ {};
+
// Incomplete array types are not constructible
template <class _Ap>
@@ -3317,6 +3366,11 @@ struct __is_constructible2_imp<false, _Ap[], _A0, _A1>
: public false_type
{};
+template <class _Ap, class _A0, class _A1, class _A2>
+struct __is_constructible3_imp<false, _Ap[], _A0, _A1, _A2>
+ : public false_type
+ {};
+
#endif // __has_feature(is_constructible)
diff --git a/test/std/utilities/meta/meta.unary/meta.unary.prop/is_constructible.pass.cpp b/test/std/utilities/meta/meta.unary/meta.unary.prop/is_constructible.pass.cpp
index 1f7c32a8cc07..b90363a5c380 100644
--- a/test/std/utilities/meta/meta.unary/meta.unary.prop/is_constructible.pass.cpp
+++ b/test/std/utilities/meta/meta.unary/meta.unary.prop/is_constructible.pass.cpp
@@ -30,6 +30,7 @@ struct A
{
explicit A(int);
A(int, double);
+ A(int, long, double);
#if TEST_STD_VER >= 11
private:
#endif
@@ -106,6 +107,16 @@ void test_is_constructible()
#endif
}
+template <class T, class A0, class A1, class A2>
+void test_is_constructible()
+{
+ static_assert(( std::is_constructible<T, A0, A1, A2>::value), "");
+ LIBCPP11_STATIC_ASSERT((std::__libcpp_is_constructible<T, A0, A1, A2>::type::value), "");
+#if TEST_STD_VER > 14
+ static_assert(( std::is_constructible_v<T, A0, A1, A2>), "");
+#endif
+}
+
template <class T>
void test_is_not_constructible()
{
@@ -146,6 +157,7 @@ int main()
test_is_constructible<int, const int> ();
test_is_constructible<A, int> ();
test_is_constructible<A, int, double> ();
+ test_is_constructible<A, int, long, double> ();
test_is_constructible<int&, int&> ();
test_is_not_constructible<A> ();