mirror of
https://github.com/ecency/ecency-mobile.git
synced 2024-12-26 06:42:15 +03:00
115 lines
3.6 KiB
C++
115 lines
3.6 KiB
C++
/*!
|
|
@file
|
|
Defines `boost::hana::hash`.
|
|
|
|
@copyright Jason Rice 2016
|
|
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_HANA_HASH_HPP
|
|
#define BOOST_HANA_HASH_HPP
|
|
|
|
#include <boost/hana/fwd/hash.hpp>
|
|
|
|
#include <boost/hana/concept/hashable.hpp>
|
|
#include <boost/hana/concept/integral_constant.hpp>
|
|
#include <boost/hana/config.hpp>
|
|
#include <boost/hana/core/dispatch.hpp>
|
|
#include <boost/hana/fwd/integral_constant.hpp>
|
|
#include <boost/hana/type.hpp>
|
|
|
|
#include <type_traits>
|
|
|
|
|
|
BOOST_HANA_NAMESPACE_BEGIN
|
|
//! @cond
|
|
template <typename X>
|
|
constexpr auto hash_t::operator()(X const& x) const {
|
|
using Tag = typename hana::tag_of<X>::type;
|
|
using Hash = BOOST_HANA_DISPATCH_IF(hash_impl<Tag>,
|
|
hana::Hashable<Tag>::value
|
|
);
|
|
|
|
#ifndef BOOST_HANA_CONFIG_DISABLE_CONCEPT_CHECKS
|
|
static_assert(hana::Hashable<Tag>::value,
|
|
"hana::hash(x) requires 'x' to be Hashable");
|
|
#endif
|
|
|
|
return Hash::apply(x);
|
|
}
|
|
//! @endcond
|
|
|
|
template <typename Tag, bool condition>
|
|
struct hash_impl<Tag, when<condition>> : default_ {
|
|
template <typename X>
|
|
static constexpr auto apply(X const&) = delete;
|
|
};
|
|
|
|
namespace detail {
|
|
template <typename T, typename = void>
|
|
struct hash_integral_helper;
|
|
|
|
template <typename Member, typename T>
|
|
struct hash_integral_helper<Member T::*> {
|
|
template <typename X>
|
|
static constexpr auto apply(X const&) {
|
|
return hana::type_c<hana::integral_constant<Member T::*, X::value>>;
|
|
}
|
|
};
|
|
|
|
template <typename T>
|
|
struct hash_integral_helper<T,
|
|
typename std::enable_if<std::is_signed<T>::value>::type
|
|
> {
|
|
template <typename X>
|
|
static constexpr auto apply(X const&) {
|
|
constexpr signed long long x = X::value;
|
|
return hana::type_c<hana::integral_constant<signed long long, x>>;
|
|
}
|
|
};
|
|
|
|
template <typename T>
|
|
struct hash_integral_helper<T,
|
|
typename std::enable_if<std::is_unsigned<T>::value>::type
|
|
> {
|
|
template <typename X>
|
|
static constexpr auto apply(X const&) {
|
|
constexpr unsigned long long x = X::value;
|
|
return hana::type_c<hana::integral_constant<unsigned long long, x>>;
|
|
}
|
|
};
|
|
|
|
template <>
|
|
struct hash_integral_helper<bool> {
|
|
template <typename X>
|
|
static constexpr auto apply(X const&) {
|
|
return hana::type_c<hana::integral_constant<bool, X::value>>;
|
|
}
|
|
};
|
|
|
|
template <>
|
|
struct hash_integral_helper<char> {
|
|
template <typename X>
|
|
static constexpr auto apply(X const&) {
|
|
using T = std::conditional<std::is_signed<char>::value,
|
|
signed long long, unsigned long long
|
|
>::type;
|
|
constexpr T x = X::value;
|
|
return hana::type_c<hana::integral_constant<T, x>>;
|
|
}
|
|
};
|
|
}
|
|
|
|
template <typename Tag>
|
|
struct hash_impl<Tag, when<hana::IntegralConstant<Tag>::value>> {
|
|
template <typename X>
|
|
static constexpr auto apply(X const& x) {
|
|
using T = typename std::remove_cv<decltype(X::value)>::type;
|
|
return detail::hash_integral_helper<T>::apply(x);
|
|
}
|
|
};
|
|
BOOST_HANA_NAMESPACE_END
|
|
|
|
#endif // !BOOST_HANA_HASH_HPP
|