expected unqualified-id before 'if' Code Answer's

  ++ - error: expected unqualified-id before ‘const’ - i have seen few questions on error, don't have experience making class in c++, don't understand answers mean. should point out didn't write code. i'm getting error stated in title, , believe it's coming header file, have no idea error means , how fix it. here file: #ifndef _quicktimer_h_ #define _quicktimer_h_ #include <cstdlib> #include <string> #include <chrono> class quicktimer { public: quicktimer(const std::string& prefix = ""); ~quicktimer(); private: std::chrono::high_resolution_clock::time_point mstarttime; const std::string mprefix; }; #endif and full errors: error: expected unqualified-id before ‘const’ quicktimer(const std::string& prefix) : ^ error: expected ‘)’ before ‘const’ error: declaration of ‘~quicktimer’ non-member ~quicktimer() ^ if explain me means , what's going on, i'd appreciate it, thanks! class name ...