Automatic memory management technology in C++ memory management

Automatic memory management technology in C is used to automatically allocate and release memory, including: smart pointers: std::shared_ptr: shared ownership pointer, automatically releasing memory. std::unique_ptr: Exclusive ownership pointer, the memory is automatically released after the variable goes out of scope. Container: std::vector: dynamically resized array, automatically releasing elements when out of range. std::map: Associative container, automatically releases all key-value pairs when out of scope.

Automatic memory management technology in C memory management

Introduction
Memory management is crucial in C. Automatic memory management technology enables programmers to allocate and release memory without manual release.

Smart pointer

• ##std::shared_ptr: A pointer with shared ownership that automatically releases memory.
• std::unique_ptr: A pointer with exclusive ownership, the memory is automatically released after the variable goes out of scope.

Container

• std::vector: Dynamic array that automatically resizes when elements are added or removed.
• std::map: Ordered associative container, automatically releasing all key-value pairs.

Practical case
Use std::shared_ptr to manage objects:

#include <memory>

class MyClass { /* ... */ };

int main() {
  std::shared_ptr<MyClass> ptr1(new MyClass());
  std::shared_ptr<MyClass> ptr2 = ptr1;  // 共享所有权

  ptr1.reset();  // 设置 ptr1 为 nullptr，减少引用计数

  if (ptr2) {  // 检查 ptr2 是否有效
    // 可以访问 MyClass 的内容
  }

  return 0;
}

Use std::unique_ptr to manage Resources:

#include <memory>

class Resource { /* ... */ };

int main() {
  std::unique_ptr<Resource> res(new Resource());

  // 使用 res

  // 变量 res 超出范围时，Resource 对象将自动释放
}

Use std::vector to store objects:

#include <vector>

int main() {
  std::vector<int> numbers;
  numbers.push_back(1);
  numbers.push_back(2);
  numbers.push_back(3);

  // 访问 vector 中的元素

  // 当 vector 超出范围时，所有元素都会自动释放
}

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