tdlight/tdutils/td/utils/unique_ptr.h

107 lines
2.6 KiB
C++

//
// Copyright Aliaksei Levin (levlam@telegram.org), Arseny Smirnov (arseny30@gmail.com) 2014-2023
//
// 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)
//
#pragma once
#include <cstddef>
#include <type_traits>
#include <utility>
namespace td {
// const-correct and compiler-friendly (g++ RAM and CPU usage 10 times less than for std::unique_ptr)
// replacement for std::unique_ptr
template <class T>
class unique_ptr final {
public:
using pointer = T *;
using element_type = T;
unique_ptr() noexcept = default;
unique_ptr(const unique_ptr &) = delete;
unique_ptr &operator=(const unique_ptr &) = delete;
unique_ptr(unique_ptr &&other) noexcept : ptr_(other.release()) {
}
unique_ptr &operator=(unique_ptr &&other) noexcept {
reset(other.release());
return *this;
}
~unique_ptr() {
reset();
}
unique_ptr(std::nullptr_t) noexcept {
}
explicit unique_ptr(T *ptr) noexcept : ptr_(ptr) {
}
template <class S, class = std::enable_if_t<std::is_base_of<T, S>::value>>
unique_ptr(unique_ptr<S> &&other) noexcept : ptr_(static_cast<S *>(other.release())) {
}
template <class S, class = std::enable_if_t<std::is_base_of<T, S>::value>>
unique_ptr &operator=(unique_ptr<S> &&other) noexcept {
reset(static_cast<T *>(other.release()));
return *this;
}
void reset(T *new_ptr = nullptr) noexcept {
static_assert(sizeof(T) > 0, "Can't destroy unique_ptr with incomplete type");
delete ptr_;
ptr_ = new_ptr;
}
T *release() noexcept {
auto res = ptr_;
ptr_ = nullptr;
return res;
}
T *get() noexcept {
return ptr_;
}
const T *get() const noexcept {
return ptr_;
}
T *operator->() noexcept {
return ptr_;
}
const T *operator->() const noexcept {
return ptr_;
}
T &operator*() noexcept {
return *ptr_;
}
const T &operator*() const noexcept {
return *ptr_;
}
explicit operator bool() const noexcept {
return ptr_ != nullptr;
}
private:
T *ptr_{nullptr};
};
template <class T>
bool operator==(std::nullptr_t, const unique_ptr<T> &p) {
return !p;
}
template <class T>
bool operator==(const unique_ptr<T> &p, std::nullptr_t) {
return !p;
}
template <class T>
bool operator!=(std::nullptr_t, const unique_ptr<T> &p) {
return static_cast<bool>(p);
}
template <class T>
bool operator!=(const unique_ptr<T> &p, std::nullptr_t) {
return static_cast<bool>(p);
}
template <class Type, class... Args>
unique_ptr<Type> make_unique(Args &&...args) {
return unique_ptr<Type>(new Type(std::forward<Args>(args)...));
}
} // namespace td