libcxx/include/__fwd/variant.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___FWD_VARIANT_H
  10 #define _LIBCPP___FWD_VARIANT_H
  11
  12 #include <__config>
  13 #include <__cstddef/size_t.h>
  14
  15 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
  16 #  pragma GCC system_header
  17 #endif
  18
  19 _LIBCPP_BEGIN_NAMESPACE_STD
  20
  21 #if _LIBCPP_STD_VER >= 17
  22
  23 template <class... _Types>
  24 class _LIBCPP_TEMPLATE_VIS variant;
  25
  26 template <class _Tp>
  27 struct _LIBCPP_TEMPLATE_VIS variant_size;
  28
  29 template <class _Tp>
  30 inline constexpr size_t variant_size_v = variant_size<_Tp>::value;
  31
  32 template <size_t _Ip, class _Tp>
  33 struct _LIBCPP_TEMPLATE_VIS variant_alternative;
  34
  35 template <size_t _Ip, class _Tp>
  36 using variant_alternative_t = typename variant_alternative<_Ip, _Tp>::type;
  37
  38 inline constexpr size_t variant_npos = static_cast<size_t>(-1);
  39
  40 template <size_t _Ip, class... _Types>
  41 _LIBCPP_HIDE_FROM_ABI
  42 _LIBCPP_AVAILABILITY_THROW_BAD_VARIANT_ACCESS constexpr variant_alternative_t<_Ip, variant<_Types...>>&
  43 get(variant<_Types...>&);
  44
  45 template <size_t _Ip, class... _Types>
  46 _LIBCPP_HIDE_FROM_ABI
  47 _LIBCPP_AVAILABILITY_THROW_BAD_VARIANT_ACCESS constexpr variant_alternative_t<_Ip, variant<_Types...>>&&
  48 get(variant<_Types...>&&);
  49
  50 template <size_t _Ip, class... _Types>
  51 _LIBCPP_HIDE_FROM_ABI
  52 _LIBCPP_AVAILABILITY_THROW_BAD_VARIANT_ACCESS constexpr const variant_alternative_t<_Ip, variant<_Types...>>&
  53 get(const variant<_Types...>&);
  54
  55 template <size_t _Ip, class... _Types>
  56 _LIBCPP_HIDE_FROM_ABI
  57 _LIBCPP_AVAILABILITY_THROW_BAD_VARIANT_ACCESS constexpr const variant_alternative_t<_Ip, variant<_Types...>>&&
  58 get(const variant<_Types...>&&);
  59
  60 template <class _Tp, class... _Types>
  61 _LIBCPP_HIDE_FROM_ABI _LIBCPP_AVAILABILITY_THROW_BAD_VARIANT_ACCESS constexpr _Tp& get(variant<_Types...>&);
  62
  63 template <class _Tp, class... _Types>
  64 _LIBCPP_HIDE_FROM_ABI _LIBCPP_AVAILABILITY_THROW_BAD_VARIANT_ACCESS constexpr _Tp&& get(variant<_Types...>&&);
  65
  66 template <class _Tp, class... _Types>
  67 _LIBCPP_HIDE_FROM_ABI _LIBCPP_AVAILABILITY_THROW_BAD_VARIANT_ACCESS constexpr const _Tp& get(const variant<_Types...>&);
  68
  69 template <class _Tp, class... _Types>
  70 _LIBCPP_HIDE_FROM_ABI _LIBCPP_AVAILABILITY_THROW_BAD_VARIANT_ACCESS constexpr const _Tp&&
  71 get(const variant<_Types...>&&);
  72
  73 #endif // _LIBCPP_STD_VER >= 17
  74
  75 _LIBCPP_END_NAMESPACE_STD
  76
  77 #endif // _LIBCPP___FWD_VARIANT_H