// d2mcpp: https://github.com/mcpp-community/d2mcpp

// license: Apache-2.0

// file: src/cpp11/tests/05-move-semantics/0.cpp

//

// Exercise/练习: cpp11 | 05 - move semantics | 移动构造与触发时机

//

// Tips/提示: 观察编译器输出, 在不改变buff传递的逻辑, 使得只做一次资源的分配和释放

//

// Docs/文档:

// - https://en.cppreference.com/w/cpp/language/move_constructor

//

// Auto-Checker/自动检测命令:

//

// d2x checker move-semantics

//

import std;

import d2x;

struct Buffer {

int *data;

Buffer() : data { new int[2] {0, 1} } {

std::cout << "Buffer():" << data << std::endl;

}

Buffer(const Buffer &other) {

std::cout << "Buffer(const Buffer&):" << data << std::endl;

data = new int[2];

data[0] = other.data[0];

data[1] = other.data[1];

}

Buffer(Buffer&& other) : data { other.data } {

std::cout << "Buffer(Buffer&&):" << data << std::endl;

other.data = nullptr; // 让原对象的指针失效

}

~Buffer() {

if (data) {

std::cout << "~Buffer():" << data << std::endl;

delete[] data;

}

}

const int * data_ptr() const { return data; }

};

Buffer process(Buffer buff) {

std::cout << "process(): " << buff.data << std::endl;

return buff;

}

int main() {

{

Buffer buff1 = process(Buffer());

auto buff1DataPtr = buff1.data_ptr();

std::cout << " --- " << std::endl;

Buffer buff2(std::move(buff1));

auto buff2DataPtr = buff2.data_ptr();

d2x::check(buff1DataPtr == buff2DataPtr, "buff1DataPtr == buff2DataPtr");

Buffer buff3 = buff2;

auto buff3DataPtr = buff3.data_ptr();

d2x::check(buff2DataPtr == buff3DataPtr, "buff2DataPtr == buff3DataPtr");

Buffer buff4 = process(buff3);

auto buff4DataPtr = buff4.data_ptr();

d2x::check(buff3DataPtr == buff4DataPtr, "buff3DataPtr == buff4DataPtr");

}

d2x::wait();

return 0;

}