Files
clang-p2996/libcxx/include/__memory/ranges_construct_at.h
Nikolas Klauser 73e8e1ba8d [libc++][NFC] Qualify declval
While it's not necessary to qualify calls to `declval` it makes error messages very crypric if the declaration isn't reachable anymore

For example:
```
    /home/nikolask/llvm-projects/libcxx/build/include/c++/v1/__chrono/duration.h:53:66: error: no type named 'type' in 'std::common_type<long, long>'
        typedef chrono::duration<typename common_type<_Rep1, _Rep2>::type,
                                 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~
    /home/nikolask/llvm-projects/libcxx/build/include/c++/v1/__type_traits/common_type.h:107:14: note: in instantiation of template class 'std::common_type<std::chrono::duration<long, std::ratio<3600, 1>>, std::chrono::duration<long, std::ratio<3600, 1>>>' requested here
        : public common_type<_Tp, _Tp> {};
                 ^
    /home/nikolask/llvm-projects/libcxx/build/include/c++/v1/__chrono/duration.h:279:58: note: in instantiation of template class 'std::common_type<std::chrono::duration<long, std::ratio<3600, 1>>>' requested here
        _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR typename common_type<duration>::type operator+() const {return typename common_type<duration>::type(*this);}
                                                             ^
    /home/nikolask/llvm-projects/libcxx/build/include/c++/v1/__chrono/duration.h:308:54: note: in instantiation of template class 'std::chrono::duration<long, std::ratio<3600, 1>>' requested here
    typedef duration<     int, ratio_multiply<ratio<24>, hours::period>>         days;
                                                         ^
    /home/nikolask/llvm-projects/libcxx/build/include/c++/v1/__chrono/duration.h:280:81: error: no type named 'type' in 'std::common_type<std::chrono::duration<long, std::ratio<3600, 1>>>'
        _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR typename common_type<duration>::type operator-() const {return typename common_type<duration>::type(-__rep_);}
                                                    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~
    /home/nikolask/llvm-projects/libcxx/build/include/c++/v1/__chrono/duration.h:308:54: note: in instantiation of template class 'std::chrono::duration<long, std::ratio<3600, 1>>' requested here
    typedef duration<     int, ratio_multiply<ratio<24>, hours::period>>         days;
                                                         ^
    /home/nikolask/llvm-projects/libcxx/build/include/c++/v1/__chrono/duration.h:53:66: error: no type named 'type' in 'std::common_type<int, int>'
        typedef chrono::duration<typename common_type<_Rep1, _Rep2>::type,
                                 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~
    /home/nikolask/llvm-projects/libcxx/build/include/c++/v1/__type_traits/common_type.h:107:14: note: in instantiation of template class 'std::common_type<std::chrono::duration<int, std::ratio<86400, 1>>, std::chrono::duration<int, std::ratio<86400, 1>>>' requested here
        : public common_type<_Tp, _Tp> {};
                 ^
    /home/nikolask/llvm-projects/libcxx/build/include/c++/v1/__chrono/duration.h:279:58: note: in instantiation of template class 'std::common_type<std::chrono::duration<int, std::ratio<86400, 1>>>' requested here
        _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR typename common_type<duration>::type operator+() const {return typename common_type<duration>::type(*this);}
                                                             ^
    /home/nikolask/llvm-projects/libcxx/build/include/c++/v1/__chrono/duration.h:309:55: note: in instantiation of template class 'std::chrono::duration<int, std::ratio<86400, 1>>' requested here
    typedef duration<     int, ratio_multiply<ratio<7>,   days::period>>         weeks;
                                                          ^
    19 similar errors omitted
```
changes with qualification added to:
```
    While building module 'std' imported from /home/nikolask/llvm-projects/libcxx/libcxx/test/std/utilities/meta/meta.trans/meta.trans.other/common_type.pass.cpp:13:
    In file included from <module-includes>:17:
    In file included from /home/nikolask/llvm-projects/libcxx/build/include/c++/v1/math.h:309:
    In file included from /home/nikolask/llvm-projects/libcxx/build/include/c++/v1/limits:107:
    In file included from /home/nikolask/llvm-projects/libcxx/build/include/c++/v1/type_traits:432:
    In file included from /home/nikolask/llvm-projects/libcxx/build/include/c++/v1/__type_traits/common_reference.h:13:
    /home/nikolask/llvm-projects/libcxx/build/include/c++/v1/__type_traits/common_type.h:28:43: error: declaration of 'declval' must be imported from module 'std.utility.__utility.declval' before it is required
    using __cond_type = decltype(false ? std::declval<_Tp>() : std::declval<_Up>());
                                              ^
    /home/nikolask/llvm-projects/libcxx/build/include/c++/v1/__utility/declval.h:30:34: note: declaration here is not visible
    decltype(std::__declval<_Tp>(0)) declval() _NOEXCEPT;
                                     ^
    /home/nikolask/llvm-projects/libcxx/libcxx/test/std/utilities/meta/meta.trans/meta.trans.other/common_type.pass.cpp:13:10: fatal error: could not build module 'std'
    #include <functional>
     ~~~~~~~~^
    2 errors generated.
```

Reviewed By: ldionne, Mordante, #libc

Spies: libcxx-commits

Differential Revision: https://reviews.llvm.org/D130854
2023-01-12 18:28:41 +01:00

126 lines
3.3 KiB
C++

// -*- C++ -*-
//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#ifndef _LIBCPP___MEMORY_RANGES_CONSTRUCT_AT_H
#define _LIBCPP___MEMORY_RANGES_CONSTRUCT_AT_H
#include <__concepts/destructible.h>
#include <__config>
#include <__iterator/incrementable_traits.h>
#include <__iterator/readable_traits.h>
#include <__memory/concepts.h>
#include <__memory/construct_at.h>
#include <__ranges/access.h>
#include <__ranges/concepts.h>
#include <__ranges/dangling.h>
#include <__utility/declval.h>
#include <__utility/forward.h>
#include <__utility/move.h>
#include <new>
#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
# pragma GCC system_header
#endif
_LIBCPP_BEGIN_NAMESPACE_STD
#if _LIBCPP_STD_VER > 17
namespace ranges {
// construct_at
namespace __construct_at {
struct __fn {
template<class _Tp, class... _Args, class = decltype(
::new (std::declval<void*>()) _Tp(std::declval<_Args>()...)
)>
_LIBCPP_HIDE_FROM_ABI
constexpr _Tp* operator()(_Tp* __location, _Args&& ...__args) const {
return _VSTD::construct_at(__location, _VSTD::forward<_Args>(__args)...);
}
};
} // namespace __construct_at
inline namespace __cpo {
inline constexpr auto construct_at = __construct_at::__fn{};
} // namespace __cpo
// destroy_at
namespace __destroy_at {
struct __fn {
template <destructible _Tp>
_LIBCPP_HIDE_FROM_ABI
constexpr void operator()(_Tp* __location) const noexcept {
_VSTD::destroy_at(__location);
}
};
} // namespace __destroy_at
inline namespace __cpo {
inline constexpr auto destroy_at = __destroy_at::__fn{};
} // namespace __cpo
// destroy
namespace __destroy {
struct __fn {
template <__nothrow_input_iterator _InputIterator, __nothrow_sentinel_for<_InputIterator> _Sentinel>
requires destructible<iter_value_t<_InputIterator>>
_LIBCPP_HIDE_FROM_ABI
constexpr _InputIterator operator()(_InputIterator __first, _Sentinel __last) const noexcept {
return _VSTD::__destroy(_VSTD::move(__first), _VSTD::move(__last));
}
template <__nothrow_input_range _InputRange>
requires destructible<range_value_t<_InputRange>>
_LIBCPP_HIDE_FROM_ABI
constexpr borrowed_iterator_t<_InputRange> operator()(_InputRange&& __range) const noexcept {
return (*this)(ranges::begin(__range), ranges::end(__range));
}
};
} // namespace __destroy
inline namespace __cpo {
inline constexpr auto destroy = __destroy::__fn{};
} // namespace __cpo
// destroy_n
namespace __destroy_n {
struct __fn {
template <__nothrow_input_iterator _InputIterator>
requires destructible<iter_value_t<_InputIterator>>
_LIBCPP_HIDE_FROM_ABI
constexpr _InputIterator operator()(_InputIterator __first, iter_difference_t<_InputIterator> __n) const noexcept {
return _VSTD::destroy_n(_VSTD::move(__first), __n);
}
};
} // namespace __destroy_n
inline namespace __cpo {
inline constexpr auto destroy_n = __destroy_n::__fn{};
} // namespace __cpo
} // namespace ranges
#endif // _LIBCPP_STD_VER > 17
_LIBCPP_END_NAMESPACE_STD
#endif // _LIBCPP___MEMORY_RANGES_CONSTRUCT_AT_H