如何将字符串的运算符<<作为参数传递？

#include <iostream>
#include <string>

void printString(std::string str) {
    std::cout << str << std::endl;
}

int main() {
    std::string str = "Hello, World!";
    printString("This is a string with the << operator: " + str + "\\<<");
    return 0;
}

This is a string with the << operator: Hello, World!<<