[ismailmaj]

The function could accept an universal reference instead of an rvalue reference, this avoids the dance the caller has to do to pass a copy.

IMO it's hard to beat pass by value considering both performance and cognitive load.

[mort96]

Yeah, making it accept a universal reference would fix it...

...but that requires the argument to be a type from a template D: so you'd have to write:

    template<typename String = std::string>
    void dosomething(String &&str)

...and that's not quite right either, since you'd want it to be either an rvalue reference or a const lvalue reference