Atmosphere/stratosphere/libstratosphere/include/boost/callable_traits/detail/qualifier_flags.hpp

123 lines
4.6 KiB
C++

/*
Defines `qualifier_flags`
@Copyright Barrett Adair 2015-2017
Distributed under the Boost Software License, Version 1.0.
(See accompanying file LICENSE.md or copy at http://boost.org/LICENSE_1_0.txt)
*/
#ifndef BOOST_CLBL_TRTS_QUALIFIER_FLAGS_HPP
#define BOOST_CLBL_TRTS_QUALIFIER_FLAGS_HPP
#include <boost/callable_traits/detail/config.hpp>
namespace boost { namespace callable_traits { namespace detail {
//bit qualifier_flags used to signify cv/ref qualifiers
using qualifier_flags = std::uint32_t;
/*
| && & V C |
--------------------------------------------
0 | 0 0 0 0 | default
1 | 0 0 0 1 | const
2 | 0 0 1 0 | volatile
3 | 0 0 1 1 | const volatile
--------------------------------------------
4 | 0 1 0 0 | &
5 | 0 1 0 1 | const &
6 | 0 1 1 0 | volatile &
7 | 0 1 1 1 | const volatile &
--------------------------------------------
8 | 1 0 0 0 | &&
9 | 1 0 0 1 | const &&
10 | 1 0 1 0 | volatile &&
11 | 1 0 1 1 | const volatile &&
*/
// Flag representing the default qualifiers on a type
// or member function overload.
constexpr qualifier_flags default_ = 0;
// Flag representing a const qualifier on a type or
// member function overload.
constexpr qualifier_flags const_ = 1;
// Flag representing a volatile qualifier on a type
// or member function overload.
constexpr qualifier_flags volatile_ = 2;
#ifdef BOOST_CLBL_TRTS_DISABLE_REFERENCE_QUALIFIERS
constexpr qualifier_flags lref_ = default_;
constexpr qualifier_flags rref_ = default_;
#else
// Flag representing an lvalue reference type, or
// an lvalue-reference-qualified member function
// overload.
constexpr qualifier_flags lref_ = 4;
// Flag representing an lvalue reference type, or
// an rvalue-reference-qualified member function
// overload.
constexpr qualifier_flags rref_ = 8;
#endif //#ifdef BOOST_CLBL_TRTS_DISABLE_REFERENCE_QUALIFIERS
constexpr qualifier_flags cv_ = 3;
template<qualifier_flags Flags>
using remove_const_flag = std::integral_constant<
qualifier_flags, Flags & ~const_>;
template<qualifier_flags Flags>
using is_const = std::integral_constant<bool,
(Flags & const_) != 0>;
template<qualifier_flags Flags>
using remove_volatile_flag = std::integral_constant<
qualifier_flags, Flags & ~volatile_>;
template<typename U, typename T = typename std::remove_reference<U>::type>
using cv_of = std::integral_constant<qualifier_flags,
(std::is_const<T>::value ? const_ : default_)
| (std::is_volatile<T>::value ? volatile_ : default_)>;
template<typename T>
using ref_of = std::integral_constant<qualifier_flags,
std::is_rvalue_reference<T>::value ? rref_
: (std::is_lvalue_reference<T>::value ? lref_
: default_)>;
//bit-flag implementation of C++11 reference collapsing rules
template<qualifier_flags Existing,
qualifier_flags Other,
bool AlreadyHasRef = (Existing & (lref_ | rref_)) != 0,
bool AlreadyHasLRef = (Existing & lref_) == lref_,
bool IsAddingLRef = (Other & lref_) == lref_
>
using collapse_flags = std::integral_constant<qualifier_flags,
!AlreadyHasRef ? (Existing | Other)
: (AlreadyHasLRef ? (Existing | (Other & ~rref_))
: (IsAddingLRef ? ((Existing & ~rref_) | Other )
: (Existing | Other)))>;
template<typename T> struct flag_map { static constexpr qualifier_flags value = default_; };
template<typename T> struct flag_map<T &> { static constexpr qualifier_flags value = lref_; };
template<typename T> struct flag_map<T &&> { static constexpr qualifier_flags value = rref_; };
template<typename T> struct flag_map<T const> { static constexpr qualifier_flags value = const_; };
template<typename T> struct flag_map<T const &> { static constexpr qualifier_flags value = const_ | lref_; };
template<typename T> struct flag_map<T const &&> { static constexpr qualifier_flags value = const_ | rref_; };
template<typename T> struct flag_map<T volatile> { static constexpr qualifier_flags value = volatile_; };
template<typename T> struct flag_map<T volatile &> { static constexpr qualifier_flags value = volatile_ | lref_; };
template<typename T> struct flag_map<T volatile &&> { static constexpr qualifier_flags value = volatile_ | rref_; };
template<typename T> struct flag_map<T const volatile> { static constexpr qualifier_flags value = const_ | volatile_; };
template<typename T> struct flag_map<T const volatile &> { static constexpr qualifier_flags value = const_ | volatile_ | lref_; };
template<typename T> struct flag_map<T const volatile &&> { static constexpr qualifier_flags value = const_ | volatile_ | rref_; };
}}} // namespace boost::callable_traits::detail
#endif // #ifndef BOOST_CLBL_TRTS_QUALIFIER_FLAGS_HPP