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implement more of N4258 - Cleaning up noexcept in the standard library. Specifically add new noexcept stuff to vector and string's move-assignment operations 

llvm-svn: 245330
This commit is contained in:
Marshall Clow 2015-08-18 18:57:00 +00:00
parent d55bcf2646
commit 1378a5aec3
6 changed files with 172 additions and 28 deletions
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9
libcxx/include/memory
View File

@ -5574,6 +5574,15 @@ template <typename _Alloc>
_LIBCPP_INLINE_VISIBILITY
void __swap_allocator(_Alloc &, _Alloc &, false_type) _NOEXCEPT {}
template <typename _Alloc, typename _Traits=allocator_traits<_Alloc>>
struct __noexcept_move_assign_container : public integral_constant<bool,
_Traits::propagate_on_container_move_assignment::value
#if _LIBCPP_STD_VER > 14
|| _Traits::is_always_equal::value
#else
&& is_nothrow_move_assignable<_Alloc>::value
#endif
> {};
_LIBCPP_END_NAMESPACE_STD

22
libcxx/include/string
View File

@ -115,8 +115,8 @@ public:
basic_string& operator=(const basic_string& str);
basic_string& operator=(basic_string&& str)
noexcept(
allocator_type::propagate_on_container_move_assignment::value &&
is_nothrow_move_assignable<allocator_type>::value);
allocator_type::propagate_on_container_move_assignment::value ||
allocator_type::is_always_equal::value ); // C++17
basic_string& operator=(const value_type* s);
basic_string& operator=(value_type c);
basic_string& operator=(initializer_list<value_type>);
@ -1377,8 +1377,7 @@ public:
#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
_LIBCPP_INLINE_VISIBILITY
basic_string& operator=(basic_string&& __str)
_NOEXCEPT_(__alloc_traits::propagate_on_container_move_assignment::value &&
is_nothrow_move_assignable<allocator_type>::value);
_NOEXCEPT_((__noexcept_move_assign_container<_Allocator, __alloc_traits>::value));
#endif
_LIBCPP_INLINE_VISIBILITY basic_string& operator=(const value_type* __s) {return assign(__s);}
basic_string& operator=(value_type __c);
@ -1845,10 +1844,15 @@ private:
#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
_LIBCPP_INLINE_VISIBILITY
void __move_assign(basic_string& __str, false_type);
void __move_assign(basic_string& __str, false_type)
_NOEXCEPT_(__alloc_traits::is_always_equal::value);
_LIBCPP_INLINE_VISIBILITY
void __move_assign(basic_string& __str, true_type)
#if _LIBCPP_STD_VER > 14
_NOEXCEPT;
#else
_NOEXCEPT_(is_nothrow_move_assignable<allocator_type>::value);
#endif
#endif
_LIBCPP_INLINE_VISIBILITY
@ -2430,6 +2434,7 @@ template <class _CharT, class _Traits, class _Allocator>
inline _LIBCPP_INLINE_VISIBILITY
void
basic_string<_CharT, _Traits, _Allocator>::__move_assign(basic_string& __str, false_type)
_NOEXCEPT_(__alloc_traits::is_always_equal::value)
{
if (__alloc() != __str.__alloc())
assign(__str);
@ -2441,7 +2446,11 @@ template <class _CharT, class _Traits, class _Allocator>
inline _LIBCPP_INLINE_VISIBILITY
void
basic_string<_CharT, _Traits, _Allocator>::__move_assign(basic_string& __str, true_type)
#if _LIBCPP_STD_VER > 14
_NOEXCEPT
#else
_NOEXCEPT_(is_nothrow_move_assignable<allocator_type>::value)
#endif
{
clear();
shrink_to_fit();
@ -2454,8 +2463,7 @@ template <class _CharT, class _Traits, class _Allocator>
inline _LIBCPP_INLINE_VISIBILITY
basic_string<_CharT, _Traits, _Allocator>&
basic_string<_CharT, _Traits, _Allocator>::operator=(basic_string&& __str)
_NOEXCEPT_(__alloc_traits::propagate_on_container_move_assignment::value &&
is_nothrow_move_assignable<allocator_type>::value)
_NOEXCEPT_((__noexcept_move_assign_container<_Allocator, __alloc_traits>::value))
{
__move_assign(__str, integral_constant<bool,
__alloc_traits::propagate_on_container_move_assignment::value>());

28
libcxx/include/vector
View File

@ -51,8 +51,8 @@ public:
vector& operator=(const vector& x);
vector& operator=(vector&& x)
noexcept(
allocator_type::propagate_on_container_move_assignment::value &&
is_nothrow_move_assignable<allocator_type>::value);
allocator_type::propagate_on_container_move_assignment::value ||
allocator_type::is_always_equal::value); // C++17
vector& operator=(initializer_list<value_type> il);
template <class InputIterator>
void assign(InputIterator first, InputIterator last);
@ -175,8 +175,8 @@ public:
vector& operator=(const vector& x);
vector& operator=(vector&& x)
noexcept(
allocator_type::propagate_on_container_move_assignment::value &&
is_nothrow_move_assignable<allocator_type>::value);
allocator_type::propagate_on_container_move_assignment::value ||
allocator_type::is_always_equal::value); // C++17
vector& operator=(initializer_list<value_type> il);
template <class InputIterator>
void assign(InputIterator first, InputIterator last);
@ -562,9 +562,7 @@ public:
vector(vector&& __x, const allocator_type& __a);
_LIBCPP_INLINE_VISIBILITY
vector& operator=(vector&& __x)
_NOEXCEPT_(
__alloc_traits::propagate_on_container_move_assignment::value &&
is_nothrow_move_assignable<allocator_type>::value);
_NOEXCEPT_((__noexcept_move_assign_container<_Allocator, __alloc_traits>::value));
#endif // _LIBCPP_HAS_NO_RVALUE_REFERENCES
#ifndef _LIBCPP_HAS_NO_GENERALIZED_INITIALIZERS
_LIBCPP_INLINE_VISIBILITY
@ -787,7 +785,8 @@ private:
void __move_range(pointer __from_s, pointer __from_e, pointer __to);
void __move_assign(vector& __c, true_type)
_NOEXCEPT_(is_nothrow_move_assignable<allocator_type>::value);
void __move_assign(vector& __c, false_type);
void __move_assign(vector& __c, false_type)
_NOEXCEPT_(__alloc_traits::is_always_equal::value);
_LIBCPP_INLINE_VISIBILITY
void __destruct_at_end(pointer __new_last) _NOEXCEPT
{
@ -1303,9 +1302,7 @@ template <class _Tp, class _Allocator>
inline _LIBCPP_INLINE_VISIBILITY
vector<_Tp, _Allocator>&
vector<_Tp, _Allocator>::operator=(vector&& __x)
_NOEXCEPT_(
__alloc_traits::propagate_on_container_move_assignment::value &&
is_nothrow_move_assignable<allocator_type>::value)
_NOEXCEPT_((__noexcept_move_assign_container<_Allocator, __alloc_traits>::value))
{
__move_assign(__x, integral_constant<bool,
__alloc_traits::propagate_on_container_move_assignment::value>());
@ -1315,6 +1312,7 @@ vector<_Tp, _Allocator>::operator=(vector&& __x)
template <class _Tp, class _Allocator>
void
vector<_Tp, _Allocator>::__move_assign(vector& __c, false_type)
_NOEXCEPT_(__alloc_traits::is_always_equal::value)
{
if (__base::__alloc() != __c.__alloc())
{
@ -2213,9 +2211,7 @@ public:
vector(vector&& __v, const allocator_type& __a);
_LIBCPP_INLINE_VISIBILITY
vector& operator=(vector&& __v)
_NOEXCEPT_(
__alloc_traits::propagate_on_container_move_assignment::value &&
is_nothrow_move_assignable<allocator_type>::value);
_NOEXCEPT_((__noexcept_move_assign_container<_Allocator, __alloc_traits>::value));
#endif // _LIBCPP_HAS_NO_RVALUE_REFERENCES
#ifndef _LIBCPP_HAS_NO_GENERALIZED_INITIALIZERS
_LIBCPP_INLINE_VISIBILITY
@ -2838,9 +2834,7 @@ template <class _Allocator>
inline _LIBCPP_INLINE_VISIBILITY
vector<bool, _Allocator>&
vector<bool, _Allocator>::operator=(vector&& __v)
_NOEXCEPT_(
__alloc_traits::propagate_on_container_move_assignment::value &&
is_nothrow_move_assignable<allocator_type>::value)
_NOEXCEPT_((__noexcept_move_assign_container<_Allocator, __alloc_traits>::value))
{
__move_assign(__v, integral_constant<bool,
__storage_traits::propagate_on_container_move_assignment::value>());

41
libcxx/test/std/containers/sequences/vector.bool/move_assign_noexcept.pass.cpp
View File

@ -28,6 +28,32 @@ struct some_alloc
some_alloc(const some_alloc&);
};
template <class T>
struct some_alloc2
{
typedef T value_type;
some_alloc2() {}
some_alloc2(const some_alloc2&);
void deallocate(void*, unsigned) {}
typedef std::false_type propagate_on_container_move_assignment;
typedef std::true_type is_always_equal;
};
template <class T>
struct some_alloc3
{
typedef T value_type;
some_alloc3() {}
some_alloc3(const some_alloc3&);
void deallocate(void*, unsigned) {}
typedef std::false_type propagate_on_container_move_assignment;
typedef std::false_type is_always_equal;
};
int main()
{
#if __has_feature(cxx_noexcept)
@ -45,7 +71,22 @@ int main()
}
{
typedef std::vector<bool, some_alloc<bool>> C;
#if TEST_STD_VER > 14
static_assert( std::is_nothrow_move_assignable<C>::value, "");
#else
static_assert(!std::is_nothrow_move_assignable<C>::value, "");
#endif
}
#if TEST_STD_VER > 14
{ // POCMA false, is_always_equal true
typedef std::vector<bool, some_alloc2<bool>> C;
static_assert( std::is_nothrow_move_assignable<C>::value, "");
}
{ // POCMA false, is_always_equal false
typedef std::vector<bool, some_alloc3<bool>> C;
static_assert(!std::is_nothrow_move_assignable<C>::value, "");
}
#endif
#endif
}

44
libcxx/test/std/containers/sequences/vector/vector.cons/move_assign_noexcept.pass.cpp
View File

@ -29,6 +29,33 @@ struct some_alloc
some_alloc(const some_alloc&);
};
template <class T>
struct some_alloc2
{
typedef T value_type;
some_alloc2() {}
some_alloc2(const some_alloc2&);
void deallocate(void*, unsigned) {}
typedef std::false_type propagate_on_container_move_assignment;
typedef std::true_type is_always_equal;
};
template <class T>
struct some_alloc3
{
typedef T value_type;
some_alloc3() {}
some_alloc3(const some_alloc3&);
void deallocate(void*, unsigned) {}
typedef std::false_type propagate_on_container_move_assignment;
typedef std::false_type is_always_equal;
};
int main()
{
#if __has_feature(cxx_noexcept)
@ -46,7 +73,24 @@ int main()
}
{
typedef std::vector<MoveOnly, some_alloc<MoveOnly>> C;
// In C++17, move assignment for allocators are not allowed to throw
#if TEST_STD_VER > 14
static_assert( std::is_nothrow_move_assignable<C>::value, "");
#else
static_assert(!std::is_nothrow_move_assignable<C>::value, "");
#endif
}
#if TEST_STD_VER > 14
{ // POCMA false, is_always_equal true
typedef std::vector<MoveOnly, some_alloc2<MoveOnly>> C;
static_assert( std::is_nothrow_move_assignable<C>::value, "");
}
{ // POCMA false, is_always_equal false
typedef std::vector<MoveOnly, some_alloc3<MoveOnly>> C;
static_assert(!std::is_nothrow_move_assignable<C>::value, "");
}
#endif
#endif
}

56
libcxx/test/std/strings/basic.string/string.cons/move_assign_noexcept.pass.cpp
View File

@ -11,14 +11,18 @@
// basic_string& operator=(basic_string&& c)
// noexcept(
// allocator_type::propagate_on_container_move_assignment::value &&
// is_nothrow_move_assignable<allocator_type>::value);
// This tests a conforming extension
// allocator_traits<allocator_type>::propagate_on_container_move_assignment::value ||
// allocator_traits<allocator_type>::is_always_equal::value); // C++17
//
// before C++17, we use the conforming extension
// noexcept(
// allocator_type::propagate_on_container_move_assignment::value &&
// is_nothrow_move_assignable<allocator_type>::value);
#include <string>
#include <cassert>
#include "test_macros.h"
#include "test_allocator.h"
template <class T>
@ -28,6 +32,32 @@ struct some_alloc
some_alloc(const some_alloc&);
};
template <class T>
struct some_alloc2
{
typedef T value_type;
some_alloc2() {}
some_alloc2(const some_alloc2&);
void deallocate(void*, unsigned) {}
typedef std::false_type propagate_on_container_move_assignment;
typedef std::true_type is_always_equal;
};
template <class T>
struct some_alloc3
{
typedef T value_type;
some_alloc3() {}
some_alloc3(const some_alloc3&);
void deallocate(void*, unsigned) {}
typedef std::false_type propagate_on_container_move_assignment;
typedef std::false_type is_always_equal;
};
int main()
{
#if __has_feature(cxx_noexcept)
@ -41,7 +71,25 @@ int main()
}
{
typedef std::basic_string<char, std::char_traits<char>, some_alloc<char>> C;
#if TEST_STD_VER > 14
// if the allocators are always equal, then the move assignment can be noexcept
static_assert( std::is_nothrow_move_assignable<C>::value, "");
#else
static_assert(!std::is_nothrow_move_assignable<C>::value, "");
#endif
}
#if TEST_STD_VER > 14
{
// POCMA is false, always equal
typedef std::basic_string<char, std::char_traits<char>, some_alloc2<char>> C;
static_assert( std::is_nothrow_move_assignable<C>::value, "");
}
{
// POCMA is false, not always equal
typedef std::basic_string<char, std::char_traits<char>, some_alloc3<char>> C;
static_assert(!std::is_nothrow_move_assignable<C>::value, "");
}
#endif
#endif
}