Function returning constexpr does not compile

问题

Why doesn't this compile:
Could there be a problem with a string as a return type?

constexpr std::string fnc()
{
    return std::string("Yaba");
}

回答1:

The constructor of std::string that takes a pointer to char is not constexpr. In constexpr functions you can only use functions that are constexpr.

来源：https://stackoverflow.com/questions/7779013/function-returning-constexpr-does-not-compile