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Diffstat (limited to 'third_party/immer/immer/box.hpp')
| -rw-r--r-- | third_party/immer/immer/box.hpp | 194 |
1 files changed, 0 insertions, 194 deletions
diff --git a/third_party/immer/immer/box.hpp b/third_party/immer/immer/box.hpp deleted file mode 100644 index 0fd2961272..0000000000 --- a/third_party/immer/immer/box.hpp +++ /dev/null @@ -1,194 +0,0 @@ -// -// immer: immutable data structures for C++ -// Copyright (C) 2016, 2017, 2018 Juan Pedro Bolivar Puente -// -// This software is distributed under the Boost Software License, Version 1.0. -// See accompanying file LICENSE or copy at http://boost.org/LICENSE_1_0.txt -// - -#pragma once - -#include <immer/detail/util.hpp> -#include <immer/memory_policy.hpp> - -namespace immer { - -namespace detail { - -template <typename U, typename MP> -struct gc_atom_impl; - -template <typename U, typename MP> -struct refcount_atom_impl; - -} // namespace detail - -/*! - * Immutable box for a single value of type `T`. - * - * The box is always copiable and movable. The `T` copy or move - * operations are never called. Since a box is immutable, copying or - * moving just copy the underlying pointers. - */ -template <typename T, typename MemoryPolicy = default_memory_policy> -class box -{ - friend struct detail::gc_atom_impl<T, MemoryPolicy>; - friend struct detail::refcount_atom_impl<T, MemoryPolicy>; - - struct holder : MemoryPolicy::refcount - { - T value; - - template <typename... Args> - holder(Args&&... args) - : value{std::forward<Args>(args)...} - {} - }; - - using heap = typename MemoryPolicy::heap::type; - - holder* impl_ = nullptr; - - box(holder* impl) - : impl_{impl} - {} - -public: - using value_type = T; - using memory_policy = MemoryPolicy; - - /*! - * Constructs a box holding `T{}`. - */ - box() - : impl_{detail::make<heap, holder>()} - {} - - /*! - * Constructs a box holding `T{arg}` - */ - template <typename Arg, - typename Enable = std::enable_if_t< - !std::is_same<box, std::decay_t<Arg>>::value && - std::is_constructible<T, Arg>::value>> - box(Arg&& arg) - : impl_{detail::make<heap, holder>(std::forward<Arg>(arg))} - {} - - /*! - * Constructs a box holding `T{arg1, arg2, args...}` - */ - template <typename Arg1, typename Arg2, typename... Args> - box(Arg1&& arg1, Arg2&& arg2, Args&&... args) - : impl_{detail::make<heap, holder>(std::forward<Arg1>(arg1), - std::forward<Arg2>(arg2), - std::forward<Args>(args)...)} - {} - - friend void swap(box& a, box& b) - { - using std::swap; - swap(a.impl_, b.impl_); - } - - box(box&& other) { swap(*this, other); } - box(const box& other) - : impl_(other.impl_) - { - impl_->inc(); - } - box& operator=(box&& other) - { - swap(*this, other); - return *this; - } - box& operator=(const box& other) - { - auto aux = other; - swap(*this, aux); - return *this; - } - ~box() - { - if (impl_ && impl_->dec()) { - impl_->~holder(); - heap::deallocate(sizeof(holder), impl_); - } - } - - /*! Query the current value. */ - IMMER_NODISCARD const T& get() const { return impl_->value; } - - /*! Conversion to the boxed type. */ - operator const T&() const { return get(); } - - /*! Access via dereference */ - const T& operator*() const { return get(); } - - /*! Access via pointer member access */ - const T* operator->() const { return &get(); } - - /*! Comparison. */ - IMMER_NODISCARD bool operator==(detail::exact_t<const box&> other) const - { - return impl_ == other.value.impl_ || get() == other.value.get(); - } - // Note that the `exact_t` disambiguates comparisons against `T{}` - // directly. In that case we want to use `operator T&` and - // compare directly. We definitely never want to convert a value - // to a box (which causes an allocation) just to compare it. - IMMER_NODISCARD bool operator!=(detail::exact_t<const box&> other) const - { - return !(*this == other.value); - } - IMMER_NODISCARD bool operator<(detail::exact_t<const box&> other) const - { - return get() < other.value.get(); - } - - /*! - * Returns a new box built by applying the `fn` to the underlying - * value. - * - * @rst - * - * **Example** - * .. literalinclude:: ../example/box/box.cpp - * :language: c++ - * :dedent: 8 - * :start-after: update/start - * :end-before: update/end - * - * @endrst - */ - template <typename Fn> - IMMER_NODISCARD box update(Fn&& fn) const& - { - return std::forward<Fn>(fn)(get()); - } - template <typename Fn> - IMMER_NODISCARD box&& update(Fn&& fn) && - { - if (impl_->unique()) - impl_->value = std::forward<Fn>(fn)(std::move(impl_->value)); - else - *this = std::forward<Fn>(fn)(impl_->value); - return std::move(*this); - } -}; - -} // namespace immer - -namespace std { - -template <typename T, typename MP> -struct hash<immer::box<T, MP>> -{ - std::size_t operator()(const immer::box<T, MP>& x) const - { - return std::hash<T>{}(*x); - } -}; - -} // namespace std |