c++ - 将数据放入 C++ 中的 std::vector 是否会创建数据的拷贝？

Question

我对创建一个新的 std::vector(或调用它的 assign 方法)创建数据的拷贝感兴趣吗？

例如，

void fun(char *input) {
    std::vector<char> v(input, input+strlen(input));
    // is it safe to assume that the data input points to was COPIED into v?
}

Answer 1

是的。元素总是被复制到 STL 容器中或从中复制出来。 (至少在 C++0x 中添加移动语义之前)

编辑:以下是测试复制自己的方法:

#include <vector>
#include <iostream>

class CopyChecker
{
public:
    CopyChecker()
    {
        std::cout << "Hey, look! A new copy checker!" << std::endl;
    }
    CopyChecker(const CopyChecker& other)
    {
        std::cout << "I'm the copy checker! No, I am! Wait, the"
            " two of us are the same!" << std::endl;
    }
    ~CopyChecker()
    {
        std::cout << "Erroap=02-0304-231~No Carrier" << std::endl;
    }
};

int main()
{
    std::vector<CopyChecker> doICopy;
    doICopy.push_back(CopyChecker());
}

输出应该是:

Hey, look! A new copy checker!
I'm the copy checker! No, I am! Wait, the two of us are the same!
Erroap=02-0304-231~No Carrier
Erroap=02-0304-231~No Carrier