diff options
| -rw-r--r-- | include/memory | 26 | ||||
| -rw-r--r-- | test/std/containers/sequences/vector/vector.cons/construct_iter_iter.pass.cpp | 31 |
2 files changed, 48 insertions, 9 deletions
diff --git a/include/memory b/include/memory index b012f5bce..93f04c6fa 100644 --- a/include/memory +++ b/include/memory @@ -1502,6 +1502,12 @@ struct __alloc_traits_difference_type<_Alloc, _Ptr, true> typedef typename _Alloc::difference_type type; }; +template <class _Tp> +struct __is_default_allocator : false_type {}; + +template <class _Tp> +struct __is_default_allocator<_VSTD::allocator<_Tp> > : true_type {}; + template <class _Alloc> struct _LIBCPP_TEMPLATE_VIS allocator_traits { @@ -1615,7 +1621,7 @@ struct _LIBCPP_TEMPLATE_VIS allocator_traits static typename enable_if < - (is_same<allocator_type, allocator<_Tp> >::value + (__is_default_allocator<allocator_type>::value || !__has_construct<allocator_type, _Tp*, _Tp>::value) && is_trivially_move_constructible<_Tp>::value, void @@ -1640,23 +1646,25 @@ struct _LIBCPP_TEMPLATE_VIS allocator_traits construct(__a, _VSTD::__to_raw_pointer(__begin2), *__begin1); } - template <class _Tp> + template <class _SourceTp, class _DestTp, + class _RawSourceTp = typename remove_const<_SourceTp>::type, + class _RawDestTp = typename remove_const<_DestTp>::type> _LIBCPP_INLINE_VISIBILITY static typename enable_if < - (is_same<allocator_type, allocator<_Tp> >::value - || !__has_construct<allocator_type, _Tp*, _Tp>::value) && - is_trivially_move_constructible<_Tp>::value, + is_trivially_move_constructible<_DestTp>::value && + is_same<_RawSourceTp, _RawDestTp>::value && + (__is_default_allocator<allocator_type>::value || + !__has_construct<allocator_type, _DestTp*, _SourceTp&>::value), void >::type - __construct_range_forward(allocator_type&, _Tp* __begin1, _Tp* __end1, _Tp*& __begin2) + __construct_range_forward(allocator_type&, _SourceTp* __begin1, _SourceTp* __end1, _DestTp*& __begin2) { - typedef typename remove_const<_Tp>::type _Vp; ptrdiff_t _Np = __end1 - __begin1; if (_Np > 0) { - _VSTD::memcpy(const_cast<_Vp*>(__begin2), __begin1, _Np * sizeof(_Tp)); + _VSTD::memcpy(const_cast<_RawDestTp*>(__begin2), __begin1, _Np * sizeof(_DestTp)); __begin2 += _Np; } } @@ -1679,7 +1687,7 @@ struct _LIBCPP_TEMPLATE_VIS allocator_traits static typename enable_if < - (is_same<allocator_type, allocator<_Tp> >::value + (__is_default_allocator<allocator_type>::value || !__has_construct<allocator_type, _Tp*, _Tp>::value) && is_trivially_move_constructible<_Tp>::value, void diff --git a/test/std/containers/sequences/vector/vector.cons/construct_iter_iter.pass.cpp b/test/std/containers/sequences/vector/vector.cons/construct_iter_iter.pass.cpp index 21a7df4a7..60fe2899a 100644 --- a/test/std/containers/sequences/vector/vector.cons/construct_iter_iter.pass.cpp +++ b/test/std/containers/sequences/vector/vector.cons/construct_iter_iter.pass.cpp @@ -146,9 +146,40 @@ void test_ctor_under_alloc() { #endif } +// Initialize a vector with a different value type. +void test_ctor_with_different_value_type() { + { + // Make sure initialization is performed with each element value, not with + // a memory blob. + float array[3] = {0.0f, 1.0f, 2.0f}; + std::vector<int> v(array, array + 3); + assert(v[0] == 0); + assert(v[1] == 1); + assert(v[2] == 2); + } + struct X { int x; }; + struct Y { int y; }; + struct Z : X, Y { int z; }; + { + Z z; + Z *array[1] = { &z }; + // Though the types Z* and Y* are very similar, initialization still cannot + // be done with `memcpy`. + std::vector<Y*> v(array, array + 1); + assert(v[0] == &z); + } + { + // Though the types are different, initialization can be done with `memcpy`. + int32_t array[1] = { -1 }; + std::vector<uint32_t> v(array, array + 1); + assert(v[0] == 4294967295); + } +} + int main() { basic_test_cases(); emplaceable_concept_tests(); // See PR34898 test_ctor_under_alloc(); + test_ctor_with_different_value_type(); } |