libcruft-util/tuple.hpp

101 lines
2.4 KiB
C++

/*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
* Copyright 2015 Danny Robson <danny@nerdcruft.net>
*/
#ifndef __UTIL_TUPLE_HPP
#define __UTIL_TUPLE_HPP
#include "types.hpp"
#include <tuple>
#include <type_traits>
namespace util {
///////////////////////////////////////////////////////////////////////////
/// call a provided object with type_tag<T> for each type in a tuple
template <
typename T,
typename F,
size_t S = 0
>
typename std::enable_if<
S == std::tuple_size<T>::value,
void
>::type
for_type (F)
{ }
//-------------------------------------------------------------------------
template<
typename T,
typename F,
size_t S = 0
>
typename std::enable_if<
S < std::tuple_size<T>::value,
void
>::type
for_type (F f)
{
using E = typename std::tuple_element<S,T>::type;
f (type_tag<E> {});
for_type<T,F,S+1> (f);
}
//-------------------------------------------------------------------------
template <typename T, typename F>
auto for_type (F f, T t)
{ return for_type<decltype(t)> (f); }
///////////////////////////////////////////////////////////////////////////
/// call a provided object with each value in a tuple
template <
size_t S = 0,
typename F,
typename ...T
>
typename std::enable_if<
S == sizeof...(T),
void
>::type
for_each (F, const std::tuple<T...>&)
{ }
//-------------------------------------------------------------------------
template<
size_t S = 0,
typename F,
typename ...T
>
typename std::enable_if<
S < sizeof...(T),
void
>::type
for_each (F f, const std::tuple<T...> &t)
{
f (std::get<S> (t));
for_each<S+1,F,T...> (f, t);
}
}
#endif