initial commit

tdutils/td/utils/unique_ptr.h

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+/*
+    This file is part of TON Blockchain Library.
+
+    TON Blockchain Library is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Lesser General Public License as published by
+    the Free Software Foundation, either version 2 of the License, or
+    (at your option) any later version.
+
+    TON Blockchain Library is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Lesser General Public License for more details.
+
+    You should have received a copy of the GNU Lesser General Public License
+    along with TON Blockchain Library.  If not, see <http://www.gnu.org/licenses/>.
+
+    Copyright 2017-2019 Telegram Systems LLP
+*/
+#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 &other) = delete;
+  unique_ptr &operator=(const unique_ptr &other) = 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 {
+    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