Sprout/sprout/operation/fixed/erase_n.hpp
2019-01-07 17:47:17 +09:00

88 lines
3.3 KiB
C++

/*=============================================================================
Copyright (c) 2011-2019 Bolero MURAKAMI
https://github.com/bolero-MURAKAMI/Sprout
Distributed under the Boost Software License, Version 1.0. (See accompanying
file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
=============================================================================*/
#ifndef SPROUT_OPERATION_FIXED_ERASE_N_HPP
#define SPROUT_OPERATION_FIXED_ERASE_N_HPP
#include <sprout/config.hpp>
#include <sprout/workaround/std/cstddef.hpp>
#include <sprout/index_tuple/metafunction.hpp>
#include <sprout/container/traits.hpp>
#include <sprout/container/functions.hpp>
#include <sprout/container/indexes.hpp>
#include <sprout/iterator/operation.hpp>
namespace sprout {
namespace fixed {
namespace results {
//
// erase_n
//
template<std::size_t N, typename Container>
struct erase_n
: public sprout::container_transform_traits<
Container
>::template rebind_size<
sprout::container_traits<Container>::static_size - N
>
{
static_assert(sprout::container_traits<Container>::static_size >= N, "static_size >= N");
};
} // namespace results
namespace detail {
template<std::size_t N, typename Result, typename Container, sprout::index_t... Indexes>
inline SPROUT_CONSTEXPR Result
erase_n_impl(
Container const& cont, sprout::index_tuple<Indexes...>,
typename sprout::container_traits<Container>::difference_type pos
)
{
return sprout::remake<Result>(
cont,
sprout::size(cont) - N,
(Indexes < sprout::container_traits<Container>::static_size - N
? (Indexes < pos
? *sprout::next(sprout::internal_begin(cont), Indexes)
: *sprout::next(sprout::internal_begin(cont), Indexes + N)
)
: typename sprout::container_traits<Result>::value_type()
)...
);
}
} // namespace detail
//
// erase_n
//
template<std::size_t N, typename Container>
inline SPROUT_CONSTEXPR typename sprout::fixed::results::erase_n<N, Container>::type
erase_n(Container const& cont, typename sprout::container_traits<Container>::const_iterator pos) {
return sprout::fixed::detail::erase_n_impl<N, typename sprout::fixed::results::erase_n<N, Container>::type>(
cont,
sprout::container_indexes<typename sprout::fixed::results::erase_n<N, Container>::type>::make(),
sprout::distance(sprout::internal_begin(cont), pos)
);
}
template<std::size_t N, typename Container>
inline SPROUT_CONSTEXPR typename sprout::fixed::results::erase_n<N, Container>::type
erase_n(Container const& cont, typename sprout::container_traits<Container>::difference_type pos) {
return sprout::fixed::detail::erase_n_impl<N, typename sprout::fixed::results::erase_n<N, Container>::type>(
cont,
sprout::container_indexes<typename sprout::fixed::results::erase_n<N, Container>::type>::make(),
sprout::distance(sprout::internal_begin(cont), sprout::next(sprout::begin(cont), pos))
);
}
} // namespace fixed
namespace results {
using sprout::fixed::results::erase_n;
} // namespace results
using sprout::fixed::erase_n;
} // namespace sprout
#endif // #ifndef SPROUT_OPERATION_FIXED_ERASE_N_HPP