mirror of
https://github.com/bolero-MURAKAMI/Sprout.git
synced 2024-12-27 21:45:42 +00:00
339 lines
12 KiB
C++
339 lines
12 KiB
C++
/*=============================================================================
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Copyright (c) 2011-2016 Bolero MURAKAMI
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https://github.com/bolero-MURAKAMI/Sprout
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Distributed under the Boost Software License, Version 1.0. (See accompanying
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file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
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=============================================================================*/
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#ifndef SPROUT_UTILITY_VALUE_HOLDER_VALUE_HOLDER_HPP
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#define SPROUT_UTILITY_VALUE_HOLDER_VALUE_HOLDER_HPP
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#include <type_traits>
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#include <initializer_list>
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#include <sprout/config.hpp>
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#include <sprout/workaround/std/cstddef.hpp>
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#include <sprout/memory/addressof.hpp>
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#include <sprout/utility/swap.hpp>
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#include <sprout/utility/forward.hpp>
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#include <sprout/utility/move.hpp>
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#include <sprout/type_traits/is_constructible.hpp>
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#include <sprout/optional/in_place.hpp>
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#include <sprout/optional/exceptions.hpp>
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namespace sprout {
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namespace detail {
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template<typename T>
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struct holder_helper {
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public:
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typedef T value_type;
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typedef T& lvalue_reference;
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typedef T&& rvalue_reference;
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typedef lvalue_reference reference;
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typedef T const& const_lvalue_reference;
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typedef T const&& const_rvalue_reference;
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typedef const_lvalue_reference const_reference;
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typedef T const& mutable_or_const_reference;
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typedef T* pointer;
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typedef T const* const_pointer;
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typedef T const* mutable_or_const_pointer;
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typedef T const& param_type;
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typedef T&& movable_param_type;
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typedef T holder_type;
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public:
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static SPROUT_CONSTEXPR holder_type const& hold(param_type p) SPROUT_NOEXCEPT {
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return p;
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}
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static SPROUT_CONSTEXPR holder_type&& hold(movable_param_type p) SPROUT_NOEXCEPT {
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return sprout::move(p);
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}
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static SPROUT_CONSTEXPR reference ref(holder_type& r) SPROUT_NOEXCEPT {
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return r;
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}
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static SPROUT_CONSTEXPR const_reference ref(holder_type const& r) SPROUT_NOEXCEPT {
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return r;
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}
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static SPROUT_CONSTEXPR pointer ptr(holder_type& r) SPROUT_NOEXCEPT {
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return sprout::addressof(r);
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}
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static SPROUT_CONSTEXPR const_pointer ptr(holder_type const& r) SPROUT_NOEXCEPT {
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return sprout::addressof(r);
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}
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};
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template<typename T>
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struct holder_helper<T const> {
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public:
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typedef T value_type;
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typedef T const& lvalue_reference;
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typedef T const&& rvalue_reference;
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typedef lvalue_reference reference;
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typedef T const& const_lvalue_reference;
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typedef T const&& const_rvalue_reference;
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typedef const_lvalue_reference const_reference;
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typedef T const& mutable_or_const_reference;
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typedef T const* pointer;
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typedef T const* const_pointer;
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typedef T const* mutable_or_const_pointer;
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typedef T const& param_type;
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typedef T const&& movable_param_type;
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typedef T holder_type;
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public:
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static SPROUT_CONSTEXPR holder_type const& hold(param_type p) SPROUT_NOEXCEPT {
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return p;
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}
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static SPROUT_CONSTEXPR holder_type const&& hold(movable_param_type p) SPROUT_NOEXCEPT {
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return sprout::move(p);
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}
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static SPROUT_CONSTEXPR reference ref(holder_type& r) SPROUT_NOEXCEPT {
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return r;
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}
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static SPROUT_CONSTEXPR const_reference ref(holder_type const& r) SPROUT_NOEXCEPT {
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return r;
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}
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static SPROUT_CONSTEXPR pointer ptr(holder_type& r) SPROUT_NOEXCEPT {
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return sprout::addressof(r);
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}
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static SPROUT_CONSTEXPR const_pointer ptr(holder_type const& r) SPROUT_NOEXCEPT {
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return sprout::addressof(r);
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}
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};
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template<typename T>
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struct holder_helper<T&> {
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public:
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typedef T value_type;
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typedef T& lvalue_reference;
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typedef T& rvalue_reference;
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typedef lvalue_reference reference;
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typedef T const& const_lvalue_reference;
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typedef T const& const_rvalue_reference;
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typedef const_lvalue_reference const_reference;
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typedef T& mutable_or_const_reference;
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typedef T* pointer;
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typedef T const* const_pointer;
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typedef T* mutable_or_const_pointer;
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typedef T& param_type;
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typedef T&& movable_param_type;
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typedef T* holder_type;
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public:
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static SPROUT_CONSTEXPR holder_type hold(param_type p) SPROUT_NOEXCEPT {
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return sprout::addressof(p);
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}
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static SPROUT_CONSTEXPR reference ref(holder_type r) {
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return r ? *r
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: (throw sprout::bad_optional_access("value_holder<>: bad optional access"), *r)
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;
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}
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static SPROUT_CONSTEXPR pointer ptr(holder_type r) SPROUT_NOEXCEPT {
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return r;
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}
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};
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template<typename T>
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struct holder_helper<T const&> {
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public:
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typedef T value_type;
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typedef T const& lvalue_reference;
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typedef T const& rvalue_reference;
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typedef lvalue_reference reference;
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typedef T const& const_lvalue_reference;
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typedef T const& const_rvalue_reference;
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typedef const_lvalue_reference const_reference;
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typedef T const& mutable_or_const_reference;
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typedef T const* pointer;
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typedef T const* const_pointer;
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typedef T const* mutable_or_const_pointer;
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typedef T const& param_type;
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typedef T const&& movable_param_type;
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typedef T const* holder_type;
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public:
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static SPROUT_CONSTEXPR holder_type hold(param_type p) SPROUT_NOEXCEPT {
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return sprout::addressof(p);
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}
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static SPROUT_CONSTEXPR reference ref(holder_type r) {
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return r ? *r
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: (throw sprout::bad_optional_access("value_holder<>: bad optional access"), *r)
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;
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}
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static SPROUT_CONSTEXPR pointer ptr(holder_type r) SPROUT_NOEXCEPT {
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return r;
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}
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};
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} // namespace detail
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//
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// value_holder
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//
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template<typename T>
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class value_holder {
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public:
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typedef T type;
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private:
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typedef sprout::detail::holder_helper<type> helper_type;
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typedef typename helper_type::holder_type holder_type;
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public:
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typedef typename helper_type::value_type value_type;
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typedef typename helper_type::lvalue_reference lvalue_reference;
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typedef typename helper_type::rvalue_reference rvalue_reference;
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typedef typename helper_type::reference reference;
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typedef typename helper_type::const_lvalue_reference const_lvalue_reference;
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typedef typename helper_type::const_rvalue_reference const_rvalue_reference;
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typedef typename helper_type::const_reference const_reference;
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typedef typename helper_type::mutable_or_const_reference mutable_or_const_reference;
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typedef typename helper_type::pointer pointer;
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typedef typename helper_type::const_pointer const_pointer;
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typedef typename helper_type::mutable_or_const_pointer mutable_or_const_pointer;
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typedef typename helper_type::param_type param_type;
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typedef typename helper_type::movable_param_type movable_param_type;
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typedef lvalue_reference lvalue_reference_type;
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typedef rvalue_reference rvalue_reference_type;
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typedef reference reference_type;
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typedef mutable_or_const_reference reference_const_type;
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typedef pointer pointer_type;
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typedef mutable_or_const_pointer pointer_const_type;
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typedef param_type argument_type;
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typedef movable_param_type movable_argument_type;
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public:
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template<typename... Args>
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struct is_constructible_args
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: public sprout::is_constructible<T, Args&&...>
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{};
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public:
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static SPROUT_CONSTEXPR reference get(value_holder& t) SPROUT_NOEXCEPT {
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return helper_type::ref(t.holder_);
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}
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static SPROUT_CONSTEXPR rvalue_reference get(value_holder&& t) SPROUT_NOEXCEPT {
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return static_cast<rvalue_reference>(get(t));
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}
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static SPROUT_CONSTEXPR mutable_or_const_reference get(value_holder const& t) SPROUT_NOEXCEPT {
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return helper_type::ref(t.holder_);
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}
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static SPROUT_CONSTEXPR pointer get_pointer(value_holder& t) SPROUT_NOEXCEPT {
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return helper_type::ptr(t.holder_);
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}
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static SPROUT_CONSTEXPR pointer get_pointer(value_holder&& t) SPROUT_NOEXCEPT {
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return get_pointer(t);
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}
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static SPROUT_CONSTEXPR mutable_or_const_pointer get_pointer(value_holder const& t) SPROUT_NOEXCEPT {
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return helper_type::ptr(t.holder_);
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}
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private:
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holder_type holder_;
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public:
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SPROUT_CONSTEXPR value_holder()
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: holder_()
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{}
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value_holder(value_holder const&) = default;
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value_holder(value_holder&&) = default;
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explicit SPROUT_CONSTEXPR value_holder(argument_type p)
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: holder_(helper_type::hold(p))
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{}
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explicit SPROUT_CONSTEXPR value_holder(movable_argument_type p)
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: holder_(helper_type::hold(sprout::move(p)))
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{}
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template<
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typename... Args,
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typename = typename std::enable_if<is_constructible_args<Args...>::value>::type
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>
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explicit SPROUT_CONSTEXPR value_holder(sprout::in_place_t, Args&&... args)
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: holder_(SPROUT_FORWARD(Args, args)...)
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{}
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template<
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typename U, typename... Args,
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typename = typename std::enable_if<is_constructible_args<std::initializer_list<U>&, Args...>::value>::type
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>
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explicit SPROUT_CONSTEXPR value_holder(sprout::in_place_t, std::initializer_list<U> il, Args&&... args)
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: holder_(il, SPROUT_FORWARD(Args, args)...)
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{}
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SPROUT_CXX14_CONSTEXPR value_holder& operator=(value_holder const& rhs) {
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value_holder temp(rhs);
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temp.swap(*this);
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return *this;
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}
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SPROUT_CXX14_CONSTEXPR value_holder& operator=(value_holder&& rhs) {
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value_holder temp(sprout::move(rhs));
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temp.swap(*this);
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return *this;
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}
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SPROUT_CXX14_CONSTEXPR value_holder& operator=(argument_type p) {
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value_holder temp(p);
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temp.swap(*this);
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return *this;
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}
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SPROUT_CXX14_CONSTEXPR value_holder& operator=(movable_argument_type p) {
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value_holder temp(sprout::move(p));
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temp.swap(*this);
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return *this;
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}
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SPROUT_CXX14_CONSTEXPR void swap(value_holder& other)
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SPROUT_NOEXCEPT_IF_EXPR(sprout::swap(holder_, other.holder_))
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{
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sprout::swap(holder_, other.holder_);
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}
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SPROUT_CXX14_CONSTEXPR operator reference() {
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return helper_type::ref(holder_);
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}
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SPROUT_CONSTEXPR operator mutable_or_const_reference() const {
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return helper_type::ref(holder_);
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}
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SPROUT_CXX14_CONSTEXPR reference operator*() {
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return helper_type::ref(holder_);
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}
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SPROUT_CONSTEXPR mutable_or_const_reference operator*() const {
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return helper_type::ref(holder_);
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}
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SPROUT_CXX14_CONSTEXPR reference get() {
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return helper_type::ref(holder_);
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}
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SPROUT_CONSTEXPR mutable_or_const_reference get() const {
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return helper_type::ref(holder_);
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}
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SPROUT_CXX14_CONSTEXPR reference value() {
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return get();
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}
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SPROUT_CONSTEXPR mutable_or_const_reference value() const {
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return get();
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}
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SPROUT_CXX14_CONSTEXPR pointer operator->() SPROUT_NOEXCEPT {
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return helper_type::ptr(holder_);
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}
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SPROUT_CONSTEXPR mutable_or_const_pointer operator->() const SPROUT_NOEXCEPT {
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return helper_type::ptr(holder_);
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}
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SPROUT_CXX14_CONSTEXPR pointer get_pointer() SPROUT_NOEXCEPT {
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return helper_type::ptr(holder_);
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}
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SPROUT_CONSTEXPR mutable_or_const_pointer get_pointer() const SPROUT_NOEXCEPT {
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return helper_type::ptr(holder_);
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}
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SPROUT_CXX14_CONSTEXPR pointer get_ptr() SPROUT_NOEXCEPT {
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return get_pointer();
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}
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SPROUT_CONSTEXPR mutable_or_const_pointer get_ptr() const SPROUT_NOEXCEPT {
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return get_pointer();
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}
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SPROUT_EXPLICIT_CONVERSION SPROUT_CONSTEXPR operator bool() const SPROUT_NOEXCEPT {
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return is_initialized();
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}
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SPROUT_CONSTEXPR bool operator!() const SPROUT_NOEXCEPT {
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return !is_initialized();
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}
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SPROUT_CONSTEXPR bool is_initialized() const SPROUT_NOEXCEPT {
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return !!get_pointer();
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}
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};
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//
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// swap
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//
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template<typename T>
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inline SPROUT_CXX14_CONSTEXPR void
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swap(sprout::value_holder<T>& lhs, sprout::value_holder<T>& rhs)
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SPROUT_NOEXCEPT_IF_EXPR(lhs.swap(rhs))
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{
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lhs.swap(rhs);
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}
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} // namespace sprout
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#endif // #ifndef SPROUT_UTILITY_VALUE_HOLDER_VALUE_HOLDER_HPP
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