string - C++ Throwing same error message from different places in code -

i want throw same error different places. here's example:

int devide(int a,int b) {   if(b==0) {     throw "b must different 0";   }    return 0; }  int mod(int a,int b) {   if(b==0) {     throw "b must different 0";   }    return 0; } 

and in main function:

int main() {   try {     devide(1,0);   } catch(char const* e) {     cout << e << endl;   }   try {     mod(1,0);   } catch(char const* e) {     cout << e << endl;   }    return 0; } 

now output of program is:

b must different 0 b must different 0 

as can see, error nature same, error message different. what's best practice can follow in case, scalable? let's have 100 different types of exceptions, when throw exception devisor different 0 want same messege everywhere exception thrown.

edit: thinking 2 options:

1. for every exception may throw define own class inherit std::exception. every exception can put in exceptions.cpp.

2. i can define 1 one class myexception inherit std::exception , in constructor request error string. , can somewhere(i still can't think of put them) define static string constants describe message. instance, if have define myexception can use this:

   int devide(int a,int b) {   if(b==0) {     throw new myexception(myexception::devision_by_zero);   } } 

where myexception::devision_by_zero string constant.

i think second approach requires less coding doesn't seem pretty me.

so there better aproach 2 above?

the best can create own exception , throw that.

class exception : public std::exception {     public:                         template< typename... args >         exception( const std::string& msg, args... args );          virtual ~exception() throw ();          //! overrides std::exception         virtual const char* what() const throw();      private:         //! log message_         void log() const;      protected:         std::string message_; };  template< typename... args > exception::exception( const std::string& msg, args... args )     : message_( strfmt::format( msg, args ... ) ) {     log(); }  class myexception : public exception {     myexception() : exception( std::string("b must different 0") ) } 

if further plan exit program on uncaught exceptions, possible install termination handler, rethrow exception.

static void terminate() {     static bool tried_rethrow = false;     try     {         if ( !tried_rethrow )         {             tried_rethrow = true;             throw;         }     }     catch ( const std::runtime_error& err )     {         std::cout << err.what();     }     catch ( const exception& err )     {         std::cout << err.what();     }     catch ( ... )     {     } }  

and in main.cpp:

std::set_terminate( terminate ); 

that way possible handle uncaught exceptions @ single place.