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/// \file
// Range v3 library
//
// Copyright Andrey Diduh 2019
//
// Use, modification and distribution is subject to 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)
//
// Project home: https://github.com/ericniebler/range-v3
//
#ifndef RANGES_V3_DETAIL_BIND_BACK_HPP
#define RANGES_V3_DETAIL_BIND_BACK_HPP
#include <tuple>
#include <meta/meta.hpp>
#include <range/v3/range_fwd.hpp>
#include <range/v3/functional/invoke.hpp>
#include <range/v3/utility/tuple_algorithm.hpp>
#include <range/v3/detail/prologue.hpp>
namespace ranges
{
// bind_back like std::bind_front has no special treatment for nested
// bind-expressions or reference_wrappers; there is no need to wrap
// Callables with ranges::protect.
namespace detail
{
template<typename Fn, typename... Args>
struct bind_back_fn_
{
using tuple_t = std::tuple<Fn, Args...>;
tuple_t fn_args_;
template<typename... CallArgs>
constexpr invoke_result_t<Fn, CallArgs..., Args...> //
operator()(CallArgs &&... cargs) &&
noexcept(is_nothrow_invocable_v<Fn, CallArgs..., Args...>)
{
return tuple_apply(
[&](auto && fn, auto &&... args) -> decltype(auto) {
return invoke((decltype(fn))fn,
(CallArgs &&) cargs...,
(decltype(args))args...);
},
(std::tuple<Fn, Args...> &&) fn_args_);
}
/// \overload
template<typename... CallArgs>
constexpr invoke_result_t<Fn &, CallArgs..., Args &...>
operator()(CallArgs &&... cargs) &
noexcept(is_nothrow_invocable_v<Fn &, CallArgs..., Args &...>)
{
return tuple_apply(
[&](auto & fn, auto &... args) -> decltype(auto) {
return invoke(fn, (CallArgs &&) cargs..., args...);
},
fn_args_);
}
/// \overload
template<typename... CallArgs>
constexpr invoke_result_t<Fn const &, CallArgs..., Args const &...>
operator()(CallArgs &&... cargs) const & //
noexcept(is_nothrow_invocable_v<Fn const &, CallArgs..., Args const &...>)
{
return tuple_apply(
[&](auto & fn, auto &... args) -> decltype(auto) {
return invoke(fn, (CallArgs &&) cargs..., args...);
},
fn_args_);
}
};
/// \cond
// Unroll a few instantiations to avoid a heavy-weight tuple instantiation
template<typename Fn, typename Arg>
struct bind_back_fn_<Fn, Arg>
{
struct tuple_t
{
Fn fn_;
Arg arg_;
};
tuple_t fn_args_;
template<typename... CallArgs>
constexpr invoke_result_t<Fn, CallArgs..., Arg> //
operator()(CallArgs &&... cargs) && //
noexcept(is_nothrow_invocable_v<Fn, CallArgs..., Arg>)
{
return invoke(
(Fn &&) fn_args_.fn_, (CallArgs &&) cargs..., (Arg &&) fn_args_.arg_);
}
template<typename... CallArgs>
constexpr invoke_result_t<Fn &, CallArgs..., Arg &> //
operator()(CallArgs &&... cargs) & //
noexcept(is_nothrow_invocable_v<Fn &, CallArgs..., Arg &>)
{
return invoke(fn_args_.fn_, (CallArgs &&) cargs..., fn_args_.arg_);
}
template<typename... CallArgs>
constexpr invoke_result_t<Fn const &, CallArgs..., Arg const &> //
operator()(CallArgs &&... cargs) const & //
noexcept(is_nothrow_invocable_v<Fn const &, CallArgs..., Arg const &>)
{
return invoke(fn_args_.fn_, (CallArgs &&) cargs..., fn_args_.arg_);
}
};
template<typename Fn, typename Arg0, typename Arg1>
struct bind_back_fn_<Fn, Arg0, Arg1>
{
struct tuple_t
{
Fn fn_;
Arg0 arg0_;
Arg1 arg1_;
};
tuple_t fn_args_;
template<typename... CallArgs>
constexpr invoke_result_t<Fn, CallArgs..., Arg0, Arg1> //
operator()(CallArgs &&... cargs) && //
noexcept(is_nothrow_invocable_v<Fn, CallArgs..., Arg0, Arg1>)
{
return invoke((Fn &&) fn_args_.fn_,
(CallArgs &&) cargs...,
(Arg0 &&) fn_args_.arg0_,
(Arg1 &&) fn_args_.arg1_);
}
template<typename... CallArgs>
constexpr invoke_result_t<Fn &, CallArgs..., Arg0 &, Arg1 &> //
operator()(CallArgs &&... cargs) & //
noexcept(is_nothrow_invocable_v<Fn &, CallArgs..., Arg0 &, Arg1 &>)
{
return invoke(
fn_args_.fn_, (CallArgs &&) cargs..., fn_args_.arg0_, fn_args_.arg1_);
}
template<typename... CallArgs>
constexpr invoke_result_t<Fn const &, CallArgs..., Arg0 const &, Arg1 const &>
operator()(CallArgs &&... cargs) const &
noexcept(is_nothrow_invocable_v<Fn const &,
CallArgs...,
Arg0 const &,
Arg1 const &>)
{
return invoke(
fn_args_.fn_, (CallArgs &&) cargs..., fn_args_.arg0_, fn_args_.arg1_);
}
};
/// \endcond
template<typename Fn, typename... Args>
using bind_back_fn = bind_back_fn_<decay_t<Fn>, decay_t<Args>...>;
} // namespace detail
struct bind_back_fn
{
template<typename Fn, typename Arg1, typename... Args>
constexpr detail::bind_back_fn<Fn, Arg1, Args...> //
operator()(Fn && fn, Arg1 && arg1, Args &&... args) const
{
#if defined(__GNUC__) && !defined(__clang__) && __GNUC__ <= 5
using T = typename detail::bind_back_fn<Fn, Arg1, Args...>::tuple_t;
return {T{(Fn &&) fn, (Arg1 &&) arg1, (Args &&) args...}};
#else
return {{(Fn &&) fn, (Arg1 &&) arg1, (Args &&) args...}};
#endif
}
};
/// \ingroup group-utility
/// \sa `bind_back_fn`
RANGES_INLINE_VARIABLE(bind_back_fn, bind_back)
} // namespace ranges
#include <range/v3/detail/epilogue.hpp>
#endif // RANGES_V3_DETAIL_BIND_BACK_HPP
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