libcxx/include/__cxx03/__tuple/ignore.h

   1 //===----------------------------------------------------------------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 #ifndef _LIBCPP___TUPLE_IGNORE_H
  10 #define _LIBCPP___TUPLE_IGNORE_H
  11
  12 #include <__cxx03/__config>
  13
  14 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
  15 #  pragma GCC system_header
  16 #endif
  17
  18 #ifndef _LIBCPP_CXX03_LANG
  19
  20 _LIBCPP_BEGIN_NAMESPACE_STD
  21
  22 struct __ignore_type {
  23   template <class _Tp>
  24   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 const __ignore_type& operator=(const _Tp&) const noexcept {
  25     return *this;
  26   }
  27 };
  28
  29 #  if _LIBCPP_STD_VER >= 17
  30 inline constexpr __ignore_type ignore;
  31 #  else
  32 constexpr __ignore_type ignore;
  33 #  endif
  34
  35 _LIBCPP_END_NAMESPACE_STD
  36
  37 #endif // _LIBCPP_CXX03_LANG
  38
  39 #endif // _LIBCPP___TUPLE_IGNORE_H