mismatch example

 bool  compare_nocase(char  c1,  char  c2){
         return  toupper(c1)  ==  toupper(c2);
 }
 int  main()  {
         string  s1  =  "a  string";
         const  char  *s2  =  "A  string";
         if (mismatch(s1.begin(),  s1.end(),  s2,
           compare_nocase).first  ==  s1.end())
                 cout  <<  "Strings  are  equal\n";
 }