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