Commit Graph

1320 Commits

Author SHA1 Message Date
Jonathan Wakely
4b7a3ab82f PR libstdc++/90397 fix std::variant friend declarations
Clang diagnoses the inconsistent noexcept-specifier on the friend
declaration of __get. Add it, and also on __get_storage.

	PR libstdc++/90397
	* include/std/variant (_Variant_storage<false, Types...>::_M_storage())
	(_Variant_storage<true, Types...>::_M_reset()))
	(_Variant_storage<true, Types...>::_M_storage())): Add noexcept.
	(__get_storage): Likewise.
	(variant): Add noexcept to friend declarations for __get and
	__get_storage.

From-SVN: r271079
2019-05-10 22:41:19 +01:00
Jonathan Wakely
0e7bd559e4 Improve API docs for std::pair
* include/bits/stl_pair.h: Improve docs.
	* include/std/tuple: Likewise.

From-SVN: r270989
2019-05-07 23:46:56 +01:00
Jonathan Wakely
c34d3fd306 Improve API docs for <chrono> and <ratio>
* doc/doxygen/doxygroups.cc (std::literals): Add documentation for
	inline namespace.
	* include/std/chrono: Improve docs.
	* include/std/ratio: Do not document implementation details.
	* testsuite/20_util/ratio/cons/cons_overflow_neg.cc: Adjust dg-error
	line numbers.
	* testsuite/20_util/ratio/operations/ops_overflow_neg.cc: Likewise.

From-SVN: r270988
2019-05-07 23:46:53 +01:00
Jonathan Wakely
f61a12b395 PR libstdc++/89102 implement new common_type rules (P0435R1, P0548R1)
This change ensures that std::common_type<> is a complete type (LWG
2408), and that std::common_type<T>, std::common_type<cv T1, cv T2>, and
std::common_type<T1, T2, R...> will use program-defined specializations
for std::common_type<T1, T2> (LWG 2465).

The implementation of common_type<T1, T2, R...> is changed to use
void_t, and the specializations for duration and time_point are modified
to also use void_t instead of depending on implementation details of
common_type.

	PR libstdc++/89102
	* doc/xml/manual/intro.xml: Document DR 2408 and 2465 changes.
	* include/std/chrono (__duration_common_type_wrapper): Replace with ...
	(__duration_common_type): New helper.
	(common_type<chrono::duration<R1, P2>, chrono::duration<R2, P2>>): Use
	__duration_common_type.
	(__timepoint_common_type_wrapper): Replace with ...
	(__timepoint_common_type): New helper.
	(common_type<chrono::time_point<C, D2>, chrono::time_point<C, D2>>):
	Use __time_point_common_type.
	* include/std/type_traits (common_type<>): Define, as per LWG 2408.
	(__common_type_impl): If either argument is transformed by decay,
	use the common_type of the decayed types.
	(__common_type_impl<_Tp, _Up, _Tp, _Up>): If the types are already
	decayed, use __do_common_type_impl to get the common_type.
	(common_type<_Tp>): Use common_type<_Tp, _Tp>.
	(__do_member_type_wrapper, __member_type_wrapper)
	(__expanded_common_type_wrapper): Remove.
	(__common_type_pack, __common_type_fold): New helpers.
	(common_type<_Tp, _Up, _Vp...>): Use new helpers instead of
	__member_type_wrapper and __expanded_common_type_wrapper.
	* testsuite/20_util/common_type/requirements/explicit_instantiation.cc:
	Test zero-length template argument list.
	* testsuite/20_util/common_type/requirements/sfinae_friendly_1.cc:
	Test single argument cases and argument types that should decay.
	* testsuite/20_util/common_type/requirements/sfinae_friendly_2.cc:
	Adjust expected error.
	* testsuite/20_util/duration/literals/range_neg.cc: Use zero for
	dg-error lineno.
	* testsuite/20_util/duration/requirements/typedefs_neg1.cc: Likewise.
	* testsuite/20_util/duration/requirements/typedefs_neg2.cc: Likewise.
	* testsuite/20_util/duration/requirements/typedefs_neg3.cc: Likewise.

From-SVN: r270987
2019-05-07 23:46:39 +01:00
Jonathan Wakely
5b5032522b Fix reference to wrong class in comment
* include/std/system_error (error_category): Fix comment.

From-SVN: r270877
2019-05-04 16:52:52 +01:00
Jonathan Wakely
2f7f1aca29 Improve API docs for <system_error> header
* include/std/system_error (error_category, error_code)
	(error_condition): Improve docs.
	* libsupc++/exception: Add missing @addtogroup Doxygen command.
	* libsupc++/exception_ptr.h (exception_ptr): Link equality operators
	to class documentation. Suppress documentation for implementation
	details.
	* libsupc++/nested_exception.h (throw_with_nested, rethrow_if_nested):
	Suppress documentation for implementation details.

From-SVN: r270873
2019-05-04 15:35:29 +01:00
Jonathan Wakely
fe6fb0d159 Fix std::hash<std::error_condition>
The hash value should be based on the identity (i.e. address) of the
error_category member, not its object representation (i.e. underlying
bytes).

	* include/std/system_error (error_code): Remove friend declaration
	for hash<error_code>.
	(hash<error_code>::operator()): Use public member functions to access
	value and category.
	(hash<error_condition>::operator()): Use address of category, not
	its object representation.
	* src/c++11/compatibility-c++0x.cc (hash<error_code>::operator()):
	Use public member functions to access value and category.
	* testsuite/19_diagnostics/error_condition/hash.cc: New test.

From-SVN: r270872
2019-05-04 15:35:25 +01:00
Jonathan Wakely
b752e2c926 Remove redundant __constexpr_addressof function
The std::__addressof function is always constexpr, even in C++14, so we
can just use that.

	* include/experimental/bits/lfts_config.h: Improve doc markup.
	* include/experimental/optional: Improve docs.
	(_Has_addressof_mem, _Has_addressof_free, _Has_addressof)
	(__constexpr_addressof): Remove.
	(optional::operator->()): Use std::__addressof().
	* include/std/optional (optional::operator->()): Adjust whitespace.
	* testsuite/experimental/optional/constexpr/observers/2.cc: Check
	that operator-> is still constexpr with overloaded operator&. Change
	to compile-only test.
	* testsuite/experimental/optional/constexpr/observers/3.cc: Change to
	compile-only test.

From-SVN: r270826
2019-05-02 22:23:35 +01:00
Jonathan Wakely
8c6a71e47c Miscellaneous API doc improvements
* include/bits/basic_string.h: Fix iterator/index confusion in
	Doxygen comments.
	* include/bits/range_access.h: Fix Doxygen warnings.
	* include/bits/refwrap.h: Do not document implementation details.
	(ref, cref): Group docs with reference_wrapper.
	* include/std/fstream: Fix Doxygen markup.
	* libsupc++/initializer_list (begin, end): Group docs with
	initializer_list.

From-SVN: r270814
2019-05-02 16:46:50 +01:00
Jonathan Wakely
725708ab75 Improve docs for mutexes
* include/bits/unique_lock.h: Fix/improve doxygen markup.
	* include/std/mutex: Likewise.
	* include/std/shared_mutex: Likewise.

From-SVN: r270812
2019-05-02 16:46:42 +01:00
Jonathan Wakely
d727fdc42b Improve docs for C++17 Filesystem library
* include/bits/fs_dir.h: Fix/improve doxygen markup.
	* include/bits/fs_fwd.h: Likewise.
	* include/bits/fs_ops.h: Likewise.
	* include/bits/fs_path.h: Likewise.
	* include/std/filesystem: Likewise.

From-SVN: r270811
2019-05-02 16:46:38 +01:00
Jonathan Wakely
c05ab418b3 Improve API docs for <memory> and <scoped_allocator>
* config/allocator/new_allocator_base.h (__allocator_base): Add
	workaround for Doxygen bug #6945.
	* include/std/memory: Improve docs. Define group for pointer safety.
	* include/std/scoped_allocator: Improve docs. Use "undocumented"
	conditional to suppress documentation for implementation details.

From-SVN: r270807
2019-05-02 16:45:04 +01:00
Jonathan Wakely
19aaf81412 Improve Doxygen docs for nested namespaces
* doc/doxygen/doxygroups.cc (std::tr2, std::__gnu_cxx): Improve docs.
	(std::experimental): Add docs.
	* doc/doxygen/user.cfg.in (PREDEFINED): Expand macros for __cxx11
	namespace to nothing when generating docs.
	* include/bits/regex_constants.h (std::regex_constants): Improve docs.
	* include/std/chrono (std::chrono): Likewise.
	* include/std/functional (std::placeholders): Likewise.
	* include/std/thread (std::this_thread): Likewise.

From-SVN: r270805
2019-05-02 16:44:55 +01:00
Jonathan Wakely
4f75543dc4 PR libstdc++/61761 fix std::proj for targets without C99 cproj
The current generic implementation of __complex_proj used when cproj is
not available calculates the wrong projection, giving a different result
than given by C99's cproj.

When C99 cproj is not available but isinf and copysign are, use those to
give correct results for float, double and long double. Otherwise, and
for other specializations of std::complex, just use a generic version
that returns its argument, and so doesn't support infinities.

We might want to consider adding additional overloads of __complex_proj
to support extended types such as _Float64x, _Float128 etc.

	PR libstdc++/61761
	* include/std/complex (__complex_proj): Return parameter unchanged.
	[_GLIBCXX_USE_C99_COMPLEX] (__complex_proj): Change overloads for
	floating-point types to take std::complex arguments.
	[_GLIBCXX_USE_C99_MATH_TR1] (__complex_proj): Add overloads for
	floating-point types.
	* testsuite/26_numerics/complex/proj.cc: New test.

From-SVN: r270759
2019-05-01 01:08:36 +01:00
Nina Dinka Ranns
ec087ba34e Adding noexcept-specification on tuple constructors (LWG 2899)
2019-04-28 Nina Dinka Ranns <dinka.ranns@gmail.com>

* libstdc++-v3/include/std/tuple:
(tuple()): Add noexcept-specification.
(tuple(const _Elements&...)): Likewise
(tuple(_UElements&&...)): Likewise
(tuple(const tuple<_UElements...>&)): Likewise
(tuple(tuple<_UElements...>&&)): Likewise
(tuple(const _T1&, const _T2&)): Likewise
(tuple(_U1&&, _U2&&)): Likewise
(tuple(const tuple<_U1, _U2>&): Likewise
(tuple(tuple<_U1, _U2>&&): Likewise
(tuple(const pair<_U1, _U2>&): Likewise
(tuple(pair<_U1, _U2>&&): Likewise
* libstdc++-v3/testsuite/20_util/tuple/cons/noexcept_specs.cc: New

From-SVN: r270632
2019-04-29 00:17:50 +03:00
Jonathan Wakely
3addb7b937 Tweak C++2a uses-allocator construction utilities
The 20_util/scoped_allocator/69293_neg.cc test was failing in C++2a mode
because the expected static_assert text wasn't matched. The code is
still ill-formed in C++2a, but uses the new __uses_alloc_args function
and so fails a different static_assert. This patch adds the same string
to the new static_assert, so the test passes.

Now that G++ allows concepts to be declared without 'bool' we can use
the correct C++2a syntax for the _Std_pair concept used to constrain the
uses-allocator construction utilities.

Also add a new test to verify that pmr::polymorphic_allocator correctly
performs recursive uses-allocator construction for nested pairs in
C++2a.

	* include/std/memory (__uses_alloc_args): Add string-literal to
	static_assert, to match the one in __uses_alloc.
	[__cpp_concepts] (_Std_pair): Use C++2a syntax for concept.
	* testsuite/20_util/polymorphic_allocator/construct_c++2a.cc: Check
	for recursive uses-allocator construction of nested pairs.
	* testsuite/20_util/scoped_allocator/construct_pair_c++2a.cc:: Add
	comment.

From-SVN: r270600
2019-04-26 14:15:54 +01:00
Jonathan Wakely
ee2f721c2f PR libstdc++/90239 use uses_allocator_construction_args in <scoped_allocator>
PR libstdc++/90239
	* doc/xml/manual/status_cxx2020.xml: Amend P0591R4 status.
	* include/std/scoped_allocator [__cplusplus > 201703L]
	(scoped_allocator_adaptor::construct): Define in terms of
	uses_allocator_construction_args, as per P0591R4.
	* testsuite/20_util/scoped_allocator/construct_pair_c++2a.cc: New test.
	* testsuite/util/testsuite_allocator.h: Remove name of unused
	parameter.

From-SVN: r270588
2019-04-25 23:43:15 +01:00
Jonathan Wakely
303b226457 Use __and_v<...> instead of __and_<...>::value
* include/std/any (any::any(ValueType&&)): Use __and_v.
	* include/std/numeric (midpoint(T, T, T), midpoint(T*, T*, T*)):
	Likewise.

From-SVN: r270552
2019-04-24 17:25:21 +01:00
Jonathan Wakely
81c7cf71bf Finish implementing "Treating Unnecessary decay" (P0777R1)
* include/std/tuple (apply): Use remove_reference_t instead of decay_t
	as per P0777R1.
	* include/std/type_traits (__result_of_memfun): Use remove_reference
	instead of __remove_cvref_t and remove redundant is_same check.
	(__inv_unwrap): Use __remove_cvref_t instead of decay_t.

From-SVN: r270551
2019-04-24 17:25:17 +01:00
Jonathan Wakely
fb8b3e2993 Fix basic_string_view typedefs and enforce preconditions
The basic_string_view::pointer and basic_string_view::reference typedefs
are supposed to refer to the non-const value type.

In previous standards having traits_type::char_type different to
value_type was simply undefined, but in the C++2a draft it's ill-formed,
as changed by P1148R0. For std::basic_string and iostreams we might
want to only enforce this conditionally for __cplusplus > 201703L but
for std::basic_string_view we don't have backwards compatibility
concerns. Also add assertions to verify the _CharT argument is a
"char-like" type (non-array, trivial, standard layout type).

Also remove the non-standard basic_string_view::_M_check and
basic_string_view::_M_limit member functions, replacing them with
non-member functions that will still exist even if basic_string_view is
specialized by the program.

	* include/experimental/string_view (basic_string_view::pointer)
	(basic_string_view::reference): Fix to refer to non-const value_type.
	* include/bits/basic_string.h (basic_string): Use __sv_check and
	__sv_limit instead of basic_string_view::_M_check and
	basic_string_view::_M_limit.
	* include/std/string_view (__sv_check, __sv_limit): New
	helper functions to replace basic_string_view::_M_check and
	basic_string_view::_M_limit.
	(basic_string_view): Add static assertions to enforce ill-formed
	requirement for traits_type::char_type from P1148R0, and to enforce
	required properties of char-like types.
	(basic_string_view::pointer, basic_string_view::reference): Fix to
	refer to non-const value_type.
	(basic_string_view::operator[], basic_string_view::at)
	(basic_string_view::front, basic_string_view::back)
	(basic_string_view::data): Use const_reference and const_pointer
	typedefs for return types.
	(basic_string_view::_M_check, basic_string_view::_M_limit): Remove.
	(hash<wstring_view>): Fix argument_type typedef.
	* testsuite/21_strings/basic_string_view/modifiers/remove_prefix/
	char/1.cc: Fix expected return type of basic_string_view::data().
	* testsuite/21_strings/basic_string_view/modifiers/remove_prefix/
	wchar_t/1.cc: Likewise.
	* testsuite/21_strings/basic_string_view/modifiers/remove_suffix/
	char/1.cc: Likewise.
	* testsuite/21_strings/basic_string_view/modifiers/remove_suffix/
	wchar_t/1.cc: Likewise.
	* testsuite/21_strings/basic_string_view/requirements/traits_neg.cc:
	New test.
	* testsuite/21_strings/basic_string_view/requirements/typedefs.cc:
	Check reference and pointer typedefs.
	* testsuite/experimental/string_view/requirements/typedefs.cc:
	Likewise.
	* testsuite/experimental/string_view/modifiers/remove_prefix/char/1.cc:
	Fix expected return type of basic_string_view::data().
	* testsuite/experimental/string_view/modifiers/remove_prefix/wchar_t/
	1.cc: Likewise.
	* testsuite/experimental/string_view/modifiers/remove_suffix/char/1.cc:
	Likewise.
	* testsuite/experimental/string_view/modifiers/remove_suffix/wchar_t/
	1.cc: Likewise.

From-SVN: r270548
2019-04-24 16:17:53 +01:00
Jonathan Wakely
92750002ef PR libstdc++/90220 Fix std::any_cast for array types
Although the std::any constructors use decay_t to determine the type of
the contained value, std::any_cast should use the un-decayed type (and
so always fail for function and array types that decay to pointers).

Using remove_cv_t is correct, because the condition for std::any_cast
to return non-null is operand.type() == typeid(T) and typeid ignores
top-level cv-qualifiers.

	PR libstdc++/90220
	* include/std/any (__any_caster): Use remove_cv_t instead of decay_t.
	Avoid a runtime check for types that can never be stored in std::any.
	* testsuite/20_util/any/misc/any_cast.cc: Test std::any_cast with
	array types.

From-SVN: r270547
2019-04-24 16:17:43 +01:00
Jonathan Wakely
f9bfdfa202 PR libstdc++/90220 Fix std::any_cast for function pointers
PR libstdc++/90220 (partial)
	* include/std/any (any_cast<T>(any*), any_cast<T>(const any*)): Do
	not attempt ill-formed static_cast to pointers to non-object types.
	* testsuite/20_util/any/misc/any_cast.cc: Test std::any_cast with
	function types.

From-SVN: r270538
2019-04-24 10:46:07 +01:00
Jonathan Wakely
86a57ce103 Implement LWG 2904 for std::variant assignment
* include/std/variant (__variant_construct): Use template parameter
	type instead of equivalent decltype-specifier.
	(_Move_ctor_base<false, Types...>::_Move_ctor_base(_Move_ctor_base&&)):
	Replace forward with move.
	(_Move_ctor_base<false, Types...>::_M_destructive_move)
	(_Move_ctor_base<false, Types...>::_M_destructive_copy)
	(_Move_ctor_base<true, Types...>::_M_destructive_move)
	(_Move_ctor_base<true, Types...>::_M_destructive_copy): Only set the
	index after construction succeeds.
	(_Copy_assign_base<false, Types...>::operator=): Remove redundant
	if-constexpr checks that are always true. Use __remove_cvref_t instead
	of remove_reference so that is_nothrow_move_constructible check
	doesn't use a const rvalue parameter. In the potentially-throwing case
	construct a temporary and move assign it, as per LWG 2904.
	(_Move_assign_base<false, Types...>::operator=): Remove redundant
	if-constexpr checks that are always true. Use emplace as per LWG 2904.
	(variant::operator=(T&&)): Only use emplace conditionally, otherwise
	construct a temporary and move assign from it, as per LWG 2904.
	* testsuite/20_util/variant/exception_safety.cc: Check that
	assignment operators have strong exception safety guarantee.

From-SVN: r270525
2019-04-24 00:01:12 +01:00
Jonathan Wakely
038bc9bfd6 Implement correct std::variant triviality rules from P0602R4
The std::variant move assignment operator should not be trivial if the
variant is not trivially move constructible.

	* include/std/variant (__detail::__variant::_Traits): Make
	_S_trivial_copy_assign depend on _S_trivial_copy_ctor and make
	_S_trivial_move_assign depend on _S_trivial_move_ctor, as per
	P0602R4.
	(__detail::__variant::_Copy_assign_alias): Only depend on
	_S_trivial_copy_assign, which subsumes _S_trivial_copy_ctor now.
	* testsuite/20_util/variant/compile.cc: Correct checks for trivial
	move assignment operators.

From-SVN: r270510
2019-04-23 13:48:28 +01:00
Jonathan Wakely
06715e1cfb PR libstdc++/90165 constrain variant(T&&) constructor
Also refactor some constraints slightly to be more readable.

	PR libstdc++/90165
	* include/std/variant (variant::__not_self): New helper for the
	is_same_v<remove_cvref_t<T>, variant>==false constraints.
	(variant::__to_type_impl): Remove.
	(variant::__to_type): Add default argument to check pack size, instead
	of using __to_type_impl.
	(variant::__accepted_type): Add default argument using __not_self.
	(variant::__is_in_place_tag, variant::__not_in_place_tag): New helpers
	for variant(T&&) constructor constraint.
	(variant::variant(T&&)): Use __not_in_place_tag in constraints.
	Extract __accepted_type into a named template parameter for reuse in
	other constraints and in the exception specification.
	(variant::variant(in_place_type_t<T>, Args&&...))
	(variant::variant(in_place_type_t<T>, initializer_list<U>, Args&&...))
	(variant::variant(in_place_index_t<T>, Args&&...))
	(variant::variant(in_place_index_t<T>, initializer_list<U>, Args&&...))
	(variant::operator=T&&)): Remove redundant && from trait arguments.
	* testsuite/20_util/variant/compile.cc: Check variant(T&&) constructor
	isn't used for in_place_type or in_place_index arguments.

From-SVN: r270509
2019-04-23 13:48:18 +01:00
Jonathan Wakely
82e8c3da74 Corrections for C++2a std::unwrap_reference traits
The P0318R1 paper added to the C++2a draft recently was not the latest
version of the paper, and should have included these changes. These
changes will be made to the working draft via a Defect Report, so I'm
applying them to libstdc++ now.

	* include/std/type_traits (unwrap_reference_t): Define for C++2a.
	(unwrap_ref_decay): Remove inheritance from unwrap_reference.
	* testsuite/20_util/unwrap_reference/1.cc: Adjust test to use alias.

From-SVN: r270506
2019-04-23 11:27:14 +01:00
Jonathan Wakely
47a468bdbe Fix std::variant regression caused by never-valueless optimization
A regression was introduced by the recent changes to provide the strong
exception safety guarantee for "never valueless" types that have O(1),
non-throwing move assignment. The problematic code is:

  else if constexpr (__detail::__variant::_Never_valueless_alt<type>())
    {
      // This construction might throw:
      variant __tmp(in_place_index<_Np>, __il,
                    std::forward<_Args>(__args)...);
      // But _Never_valueless_alt<type> means this won't:
      *this = std::move(__tmp);
    }

When the variant is not assignable, the assignment is ill-formed, so
should not be attempted. When the variant has a copy assignment operator
but not a move assignment operator, the assignment performs a copy
assignment and that could throw, so should not be attempted.

The solution is to only take that branch when the variant has a move
assignment operator, which is determined by the _Traits::_S_move_assign
constant. When that is false the strong exception safety guarantee is
not possible, and so the __never_valueless function should also depend
on _S_move_assign.

While testing the fixes for this I noticed that the partial
specialization _Never_valueless_alt<basic_string<C,T,A>> incorrectly
assumed that is_nothrow_move_constructible<basic_string<C,T,A>> is
always true, but that's wrong for fully-dynamic COW strings. Fix the
partial specialization, and improve the comment describing
_Never_valueless_alt to be clear it depends on move construction as well
as move assignment.

Finally, I also observed that _Variant_storage<false, T...>::_M_valid()
was not taking advantage of the __never_valueless<T...>() function to
avoid a runtime check. Only the _Variant_storage<true, T...>::_M_valid()
function was using __never_valueless. That is also fixed.

	PR libstdc++/87431
	* include/bits/basic_string.h (_Never_valueless_alt): Make partial
	specialization also depend on is_nothrow_move_constructible.
	* include/std/variant (__detail::__variant::__never_valueless()):
	Only true if the variant would have a move assignment operator.
	(__detail::__variant::_Variant_storage<false, T...>::_M_valid()):
	Check __never_valueless<T...>().
	(variant::emplace): Only perform non-throwing move assignments
	for never-valueless alternatives if the variant has a move assignment
	operator.
	* testsuite/20_util/variant/compile.cc: Check that never-valueless
	types can be emplaced into non-assignable variants.
	* testsuite/20_util/variant/run.cc: Check that never-valueless types
	don't get copied when emplaced into non-assignable variants.

From-SVN: r270502
2019-04-23 10:55:33 +01:00
Jonathan Wakely
be46043e07 Make some std::variant helper functions noexcept
* include/std/variant (__detail::__variant::__ref_cast): Remove
	unused function.
	(__detail::__variant::_Uninitialized::_M_get)
	(__detail::__variant::__get)
	(__gen_vtable_impl::__element_by_index_or_cookie): Add noexcept.

From-SVN: r270501
2019-04-23 10:55:28 +01:00
Jonathan Wakely
5f00d0d5c2 Fix condition for std::variant to be copy constructible
The standard says the std::variant copy constructor is defined as
deleted unless all alternative types are copy constructible, but we were
making it also depend on move constructible. Fix the condition and
enhance the tests to check the semantics with pathological copy-only
types (i.e. supporting copying but having deleted moves).

The enhanced tests revealed a regression in copy assignment for
non-trivial alternative types, where the assignment would not be
performed because the condition in the _Copy_assign_base visitor is
false: is_same_v<remove_reference_t<T&>, remove_reference_t<const T&>>.

	* include/std/variant (__detail::__variant::_Traits::_S_copy_assign):
	Do not depend on whether all alternative types are move constructible.
	(__detail::__variant::_Copy_assign_base::operator=): Remove cv-quals
	from the operand when deciding whether to perform the assignment.
	* testsuite/20_util/variant/compile.cc (DeletedMoves): Define type
	with deleted move constructor and deleted move assignment operator.
	(default_ctor, copy_ctor, move_ctor, copy_assign, move_assign): Check
	behaviour of variants with DeletedMoves as an alternative.
	* testsuite/20_util/variant/run.cc (DeletedMoves): Define same type.
	(move_ctor, move_assign): Check that moving a variant with a
	DeletedMoves alternative falls back to copying instead of moving.

From-SVN: r270425
2019-04-17 20:27:27 +01:00
Jonathan Wakely
02c9b9ccff Add constexpr to std::optional::value_or(U&&)&&
In C++1z drafts up to N4606 the constexpr keyword was missing from the
detailed description of this function, despite being shown in the class
synopsis.  That was fixed editorially for N4618, but our implementation
was not corrected to match.

	* include/std/optional (optional::value_or(U&&) &&): Add missing
	constexpr specifier.
	* testsuite/20_util/optional/constexpr/observers/4.cc: Check value_or
	for disengaged optionals and rvalue optionals.
	* testsuite/20_util/optional/observers/4.cc: Likewise.

From-SVN: r270409
2019-04-17 14:13:30 +01:00
Jonathan Wakely
9d89b73c06 Add comments and style fixes to <variant>
* include/std/variant: Adjust whitespace. Add comments.
	(_Multi_array): Leave primary template undefined.
	(_Multi_array<_Tp>): Define partial specialization for base case of
	recursion.
	(__gen_vtable_impl, __gen_vtable): Remove redundant && from type
	which is always a reference.
	(__gen_vtable::_S_apply()): Remove function, inline body into
	default member initializer.
	* testsuite/20_util/variant/visit.cc: Test with noncopyable types.

From-SVN: r270238
2019-04-09 19:50:48 +01:00
Jonathan Wakely
8701cb5e0d Fix std::visit to support arbitrary callables
The __visitor_result_type helper didn't use std::invoke and so didn't
compile when the visitor was a pointer-to-member rather than a function
object. Use std::invoke_result instead.

	* include/std/variant (__variant_idx_cookie): Add member type.
	(__visitor_result_type): Remove.
	(__do_visit): Use invoke_result instead of __visitor_result_type.
	* testsuite/20_util/variant/visit.cc: New test.

From-SVN: r270237
2019-04-09 19:50:43 +01:00
Jonathan Wakely
bc203bf0da PR libstdc++/90008 remove unused capture from variant rel ops
PR libstdc++/90008
	* include/std/variant (_VARIANT_RELATION_FUNCTION_TEMPLATE): Remove
	unused capture.
	* testsuite/20_util/variant/90008.cc: New test.

From-SVN: r270236
2019-04-09 19:50:39 +01:00
Ville Voutilainen
3d01c7c2f2 Fix visit<R> for variant.
* include/std/variant (__do_visit): Add a template parameter
for enforcing same return types for visit.
(__gen_vtable_impl): Likewise.
(_S_apply_single_alt): Adjust.
(__visit_invoke_impl): New. Handle casting to void.
(__do_visit_invoke): New. Enforces same return types.
(__do_visit_invoke_r): New. Converts return types.
(__visit_invoke): Adjust.
(__gen_vtable):  Add a template parameter for enforcing
same return types for visit.
* testsuite/20_util/variant/visit_r.cc: Add a test for a visitor with
different return types.
* testsuite/20_util/variant/visit_neg.cc: New. Ensures that
visitors with different return types don't accidentally
compile with regular visitation.

From-SVN: r270216
2019-04-08 22:45:48 +03:00
Jonathan Wakely
199b20e3cb Implement std::visit<R> for C++2a (P0655R1)
* doc/xml/manual/status_cxx2020.xml: Update status.
	* include/std/variant (visit<R>): Define for C++2a (P0655R1).
	* testsuite/20_util/variant/visit_r.cc: New test.

From-SVN: r270176
2019-04-05 19:06:02 +01:00
Jonathan Wakely
10f26de915 PR libstdc++/87431 re-adjust never-valueless optimizations
Avoid creating arbitrarily large objects on the stack when emplacing
trivially copyable objects into a variant. Currently we provide the
strong exception-safety guarantee for all trivially copyable types, by
constructing a second variant and then doing a non-throwing move
assignment from the temporary. This patch restricts that behaviour to
trivially copyable types that are no larger than 256 bytes. For larger
types the object will be emplaced directly into the variant, and if its
initialization throws then the variant becomes valueless.

Also implement Antony Polukhin's suggestion to whitelist specific types
that are not trivially copyable but can be efficiently move-assigned.
Emplacing those types will never cause a variant to become valueless.
The whitelisted types are: std::shared_ptr, std::weak_ptr,
std::unique_ptr, std::function, and std::any. Additionally,
std::basic_string, std::vector, and __gnu_debug::vector are whitelisted
if their allocator traits give them a non-throwing move assignment
operator. Specifically, this means std::string is whitelisted, but
std::pmr::string is not.

As part of this patch, additional if-constexpr branches are added for
the cases where the initialization is known to be non-throwing (so the
overhead of the try-catch block can be avoided) and where a scalar is
being produced by a potentially-throwing conversion operator (so that
the overhead of constructing and move-assigning a variant is avoided).
These changes should have no semantic effect, just better codegen.

	PR libstdc++/87431 (again)
	* include/bits/basic_string.h (__variant::_Never_valueless_alt):
	Define partial specialization for basic_string.
	* include/bits/shared_ptr.h (_Never_valueless_alt): Likewise for
	shared_ptr and weak_ptr.
	* include/bits/std_function.h (_Never_valueless_alt): Likewise for
	function.
	* include/bits/stl_vector.h (_Never_valueless_alt): Likewise for
	vector.
	* include/bits/unique_ptr.h (_Never_valueless_alt): Likewise for
	unique_ptr.
	* include/debug/vector (_Never_valueless_alt): Likewise for debug
	vector.
	* include/std/any (_Never_valueless_alt): Define explicit
	specialization for any.
	* include/std/variant (_Never_valueless_alt): Define primary template.
	(__never_valueless): Use _Never_valueless_alt instead of
	is_trivially_copyable.
	(variant::emplace<N>(Args&&...)): Add special case for non-throwing
	initializations to avoid try-catch overhead. Add special case for
	scalars produced by potentially-throwing conversions. Use
	_Never_valueless_alt instead of is_trivially_copyable for the
	remaining strong exception-safety cases.
	(variant::emplace<N>(initializer_list<U>, Args&&...)): Likewise.
	* testsuite/20_util/variant/87431.cc: Run both test functions.
	* testsuite/20_util/variant/exception_safety.cc: New test.
	* testsuite/20_util/variant/run.cc: Use pmr::string instead of string,
	so the variant becomes valueless.

From-SVN: r270170
2019-04-05 17:56:09 +01:00
Jonathan Wakely
59e36c85e7 PR libstdc++/85184 remove debug assertions from std::variant
The __glibcxx_assert macro should be used to check preconditions that
users must meet, not to check postconditions that the implementation
must meet. We have tests to verify std::variant meets its
postconditions, users shouldn't pay for those checks at runtime.

	PR libstdc++/85184
	* include/std/variant (_Copy_assign_base, _Move_assign_base, variant):
	Remove assertions.
	(variant::emplace<_Tp>): Remove result of emplace<N> directly.

From-SVN: r270117
2019-04-03 10:47:51 +01:00
Jonathan Wakely
0cb78ef4bc Define std::hash specializations for C++17 PMR strings
These hash specializations should have been added when the pmr::string
and related typedefs were added.

	* include/std/string (__hash_string_base): New class template defining
	operator() for hashing strings.
	(hash<pmr::string>, hash<pmr::u8string>, hash<pmr::u16string>)
	(hash<pmr::u32string>, hash<pmr::wstring>): Define for C++17.
	* testsuite/21_strings/basic_string/hash/hash.cc: New test.
	* testsuite/21_strings/basic_string/hash/hash_char8_t.cc: New test.

From-SVN: r270116
2019-04-03 10:47:47 +01:00
Ville Voutilainen
f1ba6c5a51 Use single-visitation in variant assignment and swap and relops.
Also use indices instead of types when checking whether
variants hold the same thing.
* include/std/variant (__do_visit): Add a template parameter
for index visitation, invoke with indices if index visitation
is used.
(__variant_idx_cookie): New.
(__visit_with_index): Likewise.
(_Copy_assign_base::operator=): Do single-visitation with
an index visitor.
(_Move_assign_base::operator=): Likewise.
(_Extra_visit_slot_needed): Adjust.
(__visit_invoke): Call with indices if it's an index visitor.
(relops): Do single-visitation with an index visitor.
(swap): Likewise.
(__visitor_result_type): New.

From-SVN: r270056
2019-04-01 16:57:41 +03:00
Ville Voutilainen
337d1fec36 Don't revisit a variant we are already visiting.
* include/std/variant (__variant_construct_single): New.
(__variant_construct): Use it.
(_M_destructive_move): Likewise.
(_M_destructive_copy): Likewise.
(_Copy_assign_base::operator=): Adjust.
(_Move_assign_base::operator=): Likewise.
(swap): Likewise.

From-SVN: r269996
2019-03-28 18:18:49 +02:00
Ville Voutilainen
da97b98ad3 re PR libstdc++/89825 (Jump table for variant visitation could be shortened for never empty variants)
PR libstdc++/89825

Fix based on a suggestion by Antony Polukhin.
* include/std/variant (_Extra_visit_slot_needed): New.
(_Multi_array): Use it.
(_S_apply_all_alts): Likewise.

From-SVN: r269947
2019-03-26 17:00:05 +02:00
Ville Voutilainen
11767f80f0 re PR libstdc++/89824 (Variant jump table reserves space for __variant_cookie twice)
PR libstdc++/89824

Fix based on a suggestion by Antony Polukhin.
* include/std/variant (__gen_vtable): Don't reserve an
additional table slot, _Multi_array already does that.

From-SVN: r269941
2019-03-26 14:41:59 +02:00
Ville Voutilainen
8be4d02ba9 re PR libstdc++/89816 (std::variant move construction regressed since GCC 8.3)
PR libstdc++/89816

Fix based on a suggestion by Antony Polukhin.
* include/std/variant (__variant_construct): Capture a pointer
to the storage and visit just one variant.

From-SVN: r269940
2019-03-26 14:07:26 +02:00
Thomas Rodgers
061f457868 Integrate C++17 parallel algorithms
This is the Intel implementation of the C++17 parallel
algorithms, which has been donated to both GCC and LLVM. The upstream
project is at -

	https://reviews.llvm.org/source/pstl/

The new files in the include/pstl sub-directory are covered by the
LICENSE.txt in that sub-directory, as are the tests in
testsuite/**/pstl/*

	* include/Makefile.am (std_header): Add ${std_srcdir}/execution.
	(pstl_srcdir, pstl_builddir, pstl_headers): New variables.
	(allstamped): Add stamp-pstl.
	(install-headers): Add ptsl_builddir.
	* include/Makefile.in: Regenerate.
	* include/bits/c++config: Add pstl configuration.
	* include/pstl/LICENSE.txt: New file.
	* include/pstl/algorithm_fwd.h: New file.
	* include/pstl/algorithm_impl.h: New file.
	* include/pstl/execution_defs.h: New file.
	* include/pstl/execution_impl.h: New file.
	* include/pstl/glue_algorithm_defs.h: New file.
	* include/pstl/glue_algorithm_impl.h: New file.
	* include/pstl/glue_execution_defs.h: New file.
	* include/pstl/glue_memory_defs.h: New file.
	* include/pstl/glue_memory_impl.h: New file.
	* include/pstl/glue_numeric_defs.h: New file.
	* include/pstl/glue_numeric_impl.h: New file.
	* include/pstl/memory_impl.h: New file.
	* include/pstl/numeric_fwd.h: New file.
	* include/pstl/numeric_impl.h: New file.
	* include/pstl/parallel_backend.h: New file.
	* include/pstl/parallel_backend_tbb.h: New file.
	* include/pstl/parallel_backend_utils.h: New file.
	* include/pstl/parallel_impl.h: New file.
	* include/pstl/pstl_config.h: New file.
	* include/pstl/unseq_backend_simd.h: New file.
	* include/pstl/utils.h: New file.
	* include/std/algorithm: Include parallel algorithm implementations.
	* include/std/execution: New file.
	* include/std/memory: Include parallel algorithm implementations.
	* include/std/numeric: Include parallel algorithm implementations.
	* include/std/version: Add parallel algorithms feature test macro.
	* testsuite/util/pstl/pstl_test_config.h: New file.
	* testsuite/util/pstl/test_utils.h: New file.
	* testsuite/20_util/specialized_algorithms/pstl/uninitialized_construct.cc: New file.
	* testsuite/20_util/specialized_algorithms/pstl/uninitialized_copy_move.cc: New file.
	* testsuite/20_util/specialized_algorithms/pstl/uninitialized_fill_destroy.cc: New file.
	* testsuite/25_algorithms/pstl/alg_merge/inplace_merge.cc: New file.
	* testsuite/25_algorithms/pstl/alg_merge/merge.cc: New file.
	* testsuite/25_algorithms/pstl/alg_modifying_operations/copy_if.cc: New file.
	* testsuite/25_algorithms/pstl/alg_modifying_operations/copy_move.cc: New file.
	* testsuite/25_algorithms/pstl/alg_modifying_operations/fill.cc: New file.
	* testsuite/25_algorithms/pstl/alg_modifying_operations/generate.cc: New file.
	* testsuite/25_algorithms/pstl/alg_modifying_operations/is_partitioned.cc: New file.
	* testsuite/25_algorithms/pstl/alg_modifying_operations/partition.cc: New file.
	* testsuite/25_algorithms/pstl/alg_modifying_operations/partition_copy.cc: New file.
	* testsuite/25_algorithms/pstl/alg_modifying_operations/remove.cc: New file.
	* testsuite/25_algorithms/pstl/alg_modifying_operations/remove_copy.cc: New file.
	* testsuite/25_algorithms/pstl/alg_modifying_operations/replace.cc: New file.
	* testsuite/25_algorithms/pstl/alg_modifying_operations/replace_copy.cc: New file.
	* testsuite/25_algorithms/pstl/alg_modifying_operations/rotate.cc: New file.
	* testsuite/25_algorithms/pstl/alg_modifying_operations/rotate_copy.cc: New file.
	* testsuite/25_algorithms/pstl/alg_modifying_operations/swap_ranges.cc: New file.
	* testsuite/25_algorithms/pstl/alg_modifying_operations/transform_binary.cc: New file.
	* testsuite/25_algorithms/pstl/alg_modifying_operations/transform_unary.cc: New file.
	* testsuite/25_algorithms/pstl/alg_modifying_operations/unique.cc: New file.
	* testsuite/25_algorithms/pstl/alg_modifying_operations/unique_copy_equal.cc: New file.
	* testsuite/25_algorithms/pstl/alg_nonmodifying/adjacent_find.cc: New file.
	* testsuite/25_algorithms/pstl/alg_nonmodifying/all_of.cc: New file.
	* testsuite/25_algorithms/pstl/alg_nonmodifying/any_of.cc: New file.
	* testsuite/25_algorithms/pstl/alg_nonmodifying/count.cc: New file.
	* testsuite/25_algorithms/pstl/alg_nonmodifying/equal.cc: New file.
	* testsuite/25_algorithms/pstl/alg_nonmodifying/find.cc: New file.
	* testsuite/25_algorithms/pstl/alg_nonmodifying/find_end.cc: New file.
	* testsuite/25_algorithms/pstl/alg_nonmodifying/find_first_of.cc: New file.
	* testsuite/25_algorithms/pstl/alg_nonmodifying/find_if.cc: New file.
	* testsuite/25_algorithms/pstl/alg_nonmodifying/for_each.cc: New file.
	* testsuite/25_algorithms/pstl/alg_nonmodifying/mismatch.cc: New file.
	* testsuite/25_algorithms/pstl/alg_nonmodifying/none_of.cc: New file.
	* testsuite/25_algorithms/pstl/alg_nonmodifying/nth_element.cc: New file.
	* testsuite/25_algorithms/pstl/alg_nonmodifying/reverse.cc: New file.
	* testsuite/25_algorithms/pstl/alg_nonmodifying/reverse_copy.cc: New file.
	* testsuite/25_algorithms/pstl/alg_nonmodifying/search_n.cc: New file.
	* testsuite/25_algorithms/pstl/alg_sorting/includes.cc: New file.
	* testsuite/25_algorithms/pstl/alg_sorting/is_heap.cc: New file.
	* testsuite/25_algorithms/pstl/alg_sorting/is_sorted.cc: New file.
	* testsuite/25_algorithms/pstl/alg_sorting/lexicographical_compare.cc: New file.
	* testsuite/25_algorithms/pstl/alg_sorting/minmax_element.cc: New file.
	* testsuite/25_algorithms/pstl/alg_sorting/partial_sort.cc: New file.
	* testsuite/25_algorithms/pstl/alg_sorting/partial_sort_copy.cc: New file.
	* testsuite/25_algorithms/pstl/alg_sorting/set.cc: New file.
	* testsuite/25_algorithms/pstl/alg_sorting/sort.cc: New file.
	* testsuite/26_numerics/pstl/numeric_ops/adjacent_difference.cc: New file.
	* testsuite/26_numerics/pstl/numeric_ops/reduce.cc: New file.
	* testsuite/26_numerics/pstl/numeric_ops/scan.cc: New file.
	* testsuite/26_numerics/pstl/numeric_ops/transform_reduce.cc: New file.
	* testsuite/26_numerics/pstl/numeric_ops/transform_scan.cc: New file.
	* testsuite/testsuite/20_util/specialized_algorithms/pstl/uninitialized_construct.cc: New file.
	* testsuite/testsuite/20_util/specialized_algorithms/pstl/uninitialized_copy_move.cc: New file.
	* testsuite/testsuite/20_util/specialized_algorithms/pstl/uninitialized_fill_destroy.cc: New file.
	* testsuite/testsuite/25_algorithms/pstl/alg_merge/inplace_merge.cc: New file.
	* testsuite/testsuite/25_algorithms/pstl/alg_merge/merge.cc: New file.
	* testsuite/testsuite/25_algorithms/pstl/alg_modifying_operations/copy_if.cc: New file.
	* testsuite/testsuite/25_algorithms/pstl/alg_modifying_operations/copy_move.cc: New file.
	* testsuite/testsuite/25_algorithms/pstl/alg_modifying_operations/fill.cc: New file.
	* testsuite/testsuite/25_algorithms/pstl/alg_modifying_operations/generate.cc: New file.
	* testsuite/testsuite/25_algorithms/pstl/alg_modifying_operations/is_partitioned.cc: New file.
	* testsuite/testsuite/25_algorithms/pstl/alg_modifying_operations/partition.cc: New file.
	* testsuite/testsuite/25_algorithms/pstl/alg_modifying_operations/partition_copy.cc: New file.
	* testsuite/testsuite/25_algorithms/pstl/alg_modifying_operations/remove.cc: New file.
	* testsuite/testsuite/25_algorithms/pstl/alg_modifying_operations/remove_copy.cc: New file.
	* testsuite/testsuite/25_algorithms/pstl/alg_modifying_operations/replace.cc: New file.
	* testsuite/testsuite/25_algorithms/pstl/alg_modifying_operations/replace_copy.cc: New file.
	* testsuite/testsuite/25_algorithms/pstl/alg_modifying_operations/rotate.cc: New file.
	* testsuite/testsuite/25_algorithms/pstl/alg_modifying_operations/rotate_copy.cc: New file.
	* testsuite/testsuite/25_algorithms/pstl/alg_modifying_operations/swap_ranges.cc: New file.
	* testsuite/testsuite/25_algorithms/pstl/alg_modifying_operations/transform_binary.cc: New file.
	* testsuite/testsuite/25_algorithms/pstl/alg_modifying_operations/transform_unary.cc: New file.
	* testsuite/testsuite/25_algorithms/pstl/alg_modifying_operations/unique.cc: New file.
	* testsuite/testsuite/25_algorithms/pstl/alg_modifying_operations/unique_copy_equal.cc: New file.
	* testsuite/testsuite/25_algorithms/pstl/alg_nonmodifying/adjacent_find.cc: New file.
	* testsuite/testsuite/25_algorithms/pstl/alg_nonmodifying/all_of.cc: New file.
	* testsuite/testsuite/25_algorithms/pstl/alg_nonmodifying/any_of.cc: New file.
	* testsuite/testsuite/25_algorithms/pstl/alg_nonmodifying/count.cc: New file.
	* testsuite/testsuite/25_algorithms/pstl/alg_nonmodifying/equal.cc: New file.
	* testsuite/testsuite/25_algorithms/pstl/alg_nonmodifying/find.cc: New file.
	* testsuite/testsuite/25_algorithms/pstl/alg_nonmodifying/find_end.cc: New file.
	* testsuite/testsuite/25_algorithms/pstl/alg_nonmodifying/find_first_of.cc: New file.
	* testsuite/testsuite/25_algorithms/pstl/alg_nonmodifying/find_if.cc: New file.
	* testsuite/testsuite/25_algorithms/pstl/alg_nonmodifying/for_each.cc: New file.
	* testsuite/testsuite/25_algorithms/pstl/alg_nonmodifying/mismatch.cc: New file.
	* testsuite/testsuite/25_algorithms/pstl/alg_nonmodifying/none_of.cc: New file.
	* testsuite/testsuite/25_algorithms/pstl/alg_nonmodifying/nth_element.cc: New file.
	* testsuite/testsuite/25_algorithms/pstl/alg_nonmodifying/reverse.cc: New file.
	* testsuite/testsuite/25_algorithms/pstl/alg_nonmodifying/reverse_copy.cc: New file.
	* testsuite/testsuite/25_algorithms/pstl/alg_nonmodifying/search_n.cc: New file.
	* testsuite/testsuite/25_algorithms/pstl/alg_sorting/includes.cc: New file.
	* testsuite/testsuite/25_algorithms/pstl/alg_sorting/is_heap.cc: New file.
	* testsuite/testsuite/25_algorithms/pstl/alg_sorting/is_sorted.cc: New file.
	* testsuite/testsuite/25_algorithms/pstl/alg_sorting/lexicographical_compare.cc: New file.
	* testsuite/testsuite/25_algorithms/pstl/alg_sorting/minmax_element.cc: New file.
	* testsuite/testsuite/25_algorithms/pstl/alg_sorting/partial_sort.cc: New file.
	* testsuite/testsuite/25_algorithms/pstl/alg_sorting/partial_sort_copy.cc: New file.
	* testsuite/testsuite/25_algorithms/pstl/alg_sorting/set.cc: New file.
	* testsuite/testsuite/25_algorithms/pstl/alg_sorting/sort.cc: New file.
	* testsuite/testsuite/26_numerics/pstl/numeric_ops/adjacent_difference.cc: New file.
	* testsuite/testsuite/26_numerics/pstl/numeric_ops/reduce.cc: New file.
	* testsuite/testsuite/26_numerics/pstl/numeric_ops/scan.cc: New file.
	* testsuite/testsuite/26_numerics/pstl/numeric_ops/transform_reduce.cc: New file.
	* testsuite/testsuite/26_numerics/pstl/numeric_ops/transform_scan.cc: New file.

From-SVN: r269863
2019-03-21 23:48:49 +00:00
Jakub Jelinek
8b9482b2d7 re PR libstdc++/89641 (std::atomic<T> no longer works)
PR libstdc++/89641
	* include/std/atomic (atomic<T>::store, atomic<T>::load,
	atomic<T>::exchange, atomic<T>::compare_exchange_weak,
	atomic<T>::compare_exchange_strong): Cast __m or __s and __f to int.
	* include/bits/atomic_base.h (__atomic_base<T>::operator++,
	__atomic_base<T>::operator--, __atomic_base<T>::operator+=,
	__atomic_base<T>::operator-=, __atomic_base<T>::operator&=,
	__atomic_base<T>::operator|=, __atomic_base<T>::operator^=,
	__atomic_base<T*>::operator++, __atomic_base<T*>::operator--,
	__atomic_base<T*>::operator+=, __atomic_base<T*>::operator-=): Cast
	memory_order_seq_cst to int.

From-SVN: r269582
2019-03-11 12:49:13 +01:00
Jonathan Wakely
9ae2a7c399 P0356R5 Simplified partial function application
* include/std/functional [C++20] (_Bind_front, _Bind_front_t): Define
	helpers for bind_front.
	(bind_front, __cpp_lib_bind_front): Define.
	* testsuite/20_util/function_objects/bind_front/1.cc: New test.

From-SVN: r269455
2019-03-07 14:15:53 +00:00
Jonathan Wakely
4661094069 Add feature test macro for bounded array traits
* include/std/type_traits (__cpp_lib_bounded_array_traits): Define.
	* include/std/version (__cpp_lib_bounded_array_traits): Likewise.
	* testsuite/20_util/is_bounded_array/value.cc: Check for macro.
	* testsuite/20_util/is_unbounded_array/value.cc: Likewise.

From-SVN: r269426
2019-03-06 15:31:06 +00:00
Ville Voutilainen
669a6fdcb4 Rewrite variant, also PR libstdc++/85517
* include/std/variant (__do_visit): New.
(__variant_cast): Likewise.
(__variant_cookie): Likewise.
(__erased_*): Remove.
(_Variant_storage::_S_vtable): Likewise.
(_Variant_storage::__M_reset_impl): Adjust to use __do_visit.
(_Variant_storage::__M_reset): Adjust.
(__variant_construct): New.
(_Copy_ctor_base(const _Copy_ctor_base&)): Adjust to use
__variant_construct.
(_Move_ctor_base(_Move_ctor_base&&)): Likewise.
(_Move_ctor_base::__M_destructive_copy): New.
(_Move_ctor_base::__M_destructive_move): Adjust to use
__variant_construct.
(_Copy_assign_base::operator=): Adjust to use __do_visit.
(_Copy_assign_alias): Adjust to check both copy assignment
and copy construction for triviality.
(_Move_assign_base::operator=): Adjust to use __do_visit.
(_Multi_array): Add support for visitors that accept and return
a __variant_cookie.
(__gen_vtable_impl::_S_apply_all_alts): Likewise.
(__gen_vtable_impl::_S_apply_single_alt): Likewise.
(__gen_vtable_impl::__element_by_index_or_cookie): New. Generate
a __variant_cookie temporary for a variant that is valueless and..
(__gen_vtable_impl::__visit_invoke): ..adjust here.
(__gen_vtable::_Array_type): Conditionally make space for
the __variant_cookie visitor case.
(__variant_construct_by_index): New.
(get_if): Adjust to use std::addressof.
(relops): Adjust to use __do_visit.
(variant): Add __variant_cast and __variant_construct_by_index
as friends.
(variant::emplace): Use _M_reset() and __variant_construct_by_index
instead of self-destruction.
(variant::swap): Adjust to use __do_visit.
(visit): Reimplement in terms of __do_visit.
(__variant_hash_call_base_impl::operator()): Adjust to use __do_visit.
* testsuite/20_util/variant/compile.cc: Adjust.
* testsuite/20_util/variant/run.cc: Likewise.

From-SVN: r269422
2019-03-06 14:56:05 +02:00
Jonathan Wakely
28d85efbfb Add C++20 Traits for [Un]bounded Arrays (P1357R1)
* include/std/type_traits [C++20] (is_bounded_array)
	 (is_unbounded_array, is_bounded_array_v, is_unbounded_array_v):
	 Define.
	 * testsuite/20_util/is_bounded_array/requirements/
	 explicit_instantiation.cc: New test.
	 * testsuite/20_util/is_bounded_array/requirements/typedefs.cc: New
	 test.
	 * testsuite/20_util/is_bounded_array/value.cc: New test.
	 * testsuite/20_util/is_unbounded_array/requirements/
	 explicit_instantiation.cc: New test.
	 * testsuite/20_util/is_unbounded_array/requirements/typedefs.cc: New
	 * test.
	 * testsuite/20_util/is_unbounded_array/value.cc: New test.

From-SVN: r269420
2019-03-06 12:13:14 +00:00
Jonathan Wakely
243874426d Define midpoint and lerp functions for C++20 (P0811R3)
The implementation of midpoint used for integral types is due to Howard
Hinnant and avoids a branch for int and larger types (but not for chars
and shorts).

The midpoint and lerp functions for floating point types come straight
from the P0811R3 proposal, with no attempt at optimization.

	* include/c_compatibility/math.h [C++20] (lerp): Add using
	declaration.
	* include/c_global/cmath [C++20] (__cpp_lib_interpolate): Define.
	(__lerp): Define function template to implement lerp.
	(lerp(float, float, float), lerp(double, double, double))
	(lerp(long double, long double, long double)): Define for C++20.
	* include/std/numeric [C++20] (__cpp_lib_interpolate): Define.
	(midpoint(T, T), midpoint(T*, T*)): Define.
	* include/std::version [C++20] (__cpp_lib_interpolate): Define.
	* testsuite/26_numerics/lerp.cc: New test.
	* testsuite/26_numerics/midpoint/floating.cc: New test.
	* testsuite/26_numerics/midpoint/integral.cc: New test.
	* testsuite/26_numerics/midpoint/pointer.cc: New test.

From-SVN: r269398
2019-03-05 18:37:24 +00:00