Templates permit to create generic functions that admit any data type as parameters and return value without having to overload the function with all the possible data types. Until particular point they fulfil the functionality of a macro. Its prototype is any of the two following ones:

template function_declaration; template function_declaration;

The only difference among both prototypes is the use of keyword class or typename, its use is indistinct since both expressions have exactly the similar meaning and behave exactly the similar way.