[Bug c++/84667] unreasonable refusal to use assignment operator method

[estellnb at elstel dot org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84667

--- Comment #3 from Elmar Stellnberger <estellnb at elstel dot org> ---
if I unify the implicit copy constructor with my own one then it also works for
g++:   xstr_mutable( const xstr& s ) : xstr(s) {}