Set default comparison type in Template

I want to set default class type as default comparison type in Template and then I want to compares two character strings using templates, I did write code but it’s giving error. Code and error is given below,

class CaseSenCmp{
public:
     static int isEqual(char x, char y){        return x==y;    }
};

template<typename c=CaseSenCmp>
int compare(char* str1, char* str2){
  for(int i=0; i<strlen(str1) && i<strlen(str2); i++)
    if(!c::isEqual(str1[i], str2[i]))
        return str1[i]-str2[i];
  return strlen(str1)-strlen(str2); 
}

main(){
char *x = "hello", *y = "HELLO";
compare(x,y);   
}

But when i have added this prototype of template, it works

template<typename c>

Compiler gives this error

error: default template arguments may not be used in function templates without -std=c++11 or -std=gnu++11|

Also when i try to do type casting in main function using this code, it also works

compare<CaseSenCmp>(x,y);

But i want to set Default Policy