https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79714
Jonathan Wakely <redi at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|UNCONFIRMED |RESOLVED Resolution|--- |INVALID --- Comment #1 from Jonathan Wakely <redi at gcc dot gnu.org> --- This is not an assignment, it's an initialization, i.e. constructor call, and there is no std::string constructor from char. There never has been. http://en.cppreference.com/w/cpp/string/basic_string/basic_string If you want a std::string containing a single character then you want: ST sSignsDot(1, c);