39 lines
1 KiB
C++
39 lines
1 KiB
C++
//
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// immer: immutable data structures for C++
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// Copyright (C) 2016, 2017, 2018 Juan Pedro Bolivar Puente
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//
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// This software is distributed under the Boost Software License, Version 1.0.
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// See accompanying file LICENSE or copy at http://boost.org/LICENSE_1_0.txt
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//
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#pragma once
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// Adapted from the official std::invoke proposal:
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// http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2014/n4169.html
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#include <type_traits>
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#include <functional>
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namespace scm {
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namespace detail {
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template <typename Functor, typename... Args>
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std::enable_if_t<
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std::is_member_pointer<std::decay_t<Functor>>::value,
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std::result_of_t<Functor&&(Args&&...)>>
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invoke(Functor&& f, Args&&... args)
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{
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return std::mem_fn(f)(std::forward<Args>(args)...);
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}
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template <typename Functor, typename... Args>
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std::enable_if_t<
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!std::is_member_pointer<std::decay_t<Functor>>::value,
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std::result_of_t<Functor&&(Args&&...)>>
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invoke(Functor&& f, Args&&... args)
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{
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return std::forward<Functor>(f)(std::forward<Args>(args)...);
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}
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} // namespace detail
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} // namespace scm
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