which is the better way to pass an empty string as function parameter in C++?

Question

I have three way to pass an empty string as function parameter as below.

void funciton(const std::string& str)
{
}

int main()
{
    //the first way is passing  ""
    funciton("");
    //the sencond way is passing  {}
    funciton({});
    //the third way is passing std::string()
    function(std::string());
    return 0;
}

I have seen that many discussions recommend to ues {} when return a empty string, and I wonder which is the better way to pass an empty string.

Answer 1

The generated output will be the same in all three cases, the best is the one that clearly shows your intent in the code, I would go with f("") . Nowadays std::string supports move semantics, so if you mostly pass them as rvalues, I wouldn't use const references. consider also this:

f(std::string s ="");
f();

And because you were using const references, check also if std::string_view could be useful in your use case.