hash operator T operator!= operator== symbol symbol

operator!= bool operator!= ( const symbol & lhs, const symbol & rhs ) friend Determines if two symbols are not equal. Parameters lhs,rhs The symbols to compare. Return values true The underlying strings of lhs and rhs are not equal. false The underlying strings of lhs and rhs are equal. Postcondition x != y if and only if (const std::string &)x != (const std::string &)y