C++ STL copy, move 用法

一：功能

        正向（从前向后的顺序）拷贝/移动操作，将一个容器元素拷贝/移动到另一容器中。

二：用法

#include <iostream>
#include <vector>
#include <algorithm>
 
int main() {
    std::vector<std::string> data{ "a", "b", "c", "d", "e", "f"};
    for (auto v : data)
        std::cout << v << " ";
    std::cout << "\n";
 
    std::copy(data.begin(), data.begin()+3, data.begin()+3);
    for (auto v : data)
        std::cout << v << " ";
    std::cout << "\n";
 
    // Overlapping case:
    std::copy(std::next(data.begin()), data.end(), data.begin());
    for (auto v : data)
        std::cout << v << " ";
    std::cout << "\n";
}

#include <iostream>
#include <vector>
#include <iomanip>
#include <algorithm>
 
int main() {
    std::vector<std::string> data{ "a", "b", "c", "d", "e", "f"};
    for (auto &v : data)
        std::cout << std::quoted(v) << " ";
    std::cout << "\n";
    //"a" "b" "c" "d" "e" "f" 
 
    std::move(data.begin(), data.begin()+3, data.begin()+3);
    for (auto &v : data)
        std::cout << std::quoted(v) << " ";
    std::cout << "\n";
    //"" "" "" "a" "b" "c" 
}

#include <iostream>
#include <vector>
#include <algorithm>
 
struct CopyOnly {
	CopyOnly() = default;
	CopyOnly(const CopyOnly&) = default;
	CopyOnly& operator=(const CopyOnly&) { 
		std::cout << "Copy assignment.\n";
		return *this;
	};
};
 
int main() {
    std::vector<CopyOnly> test(6);
    //移动操作取决于底层元素类型，如果不支持移动操作，实际还是走的拷贝操作
    std::move(test.begin(), test.begin()+3, test.begin()+3);
}