C++ Primer, Fifth Edition

Writing Overloaded Templates

As an example, we’ll build a set of functions that might be useful during debugging. We’ll name our debugging functions debug_rep, each of which will return a string representation of a given object. We’ll start by writing the most general version of this function as a template that takes a reference to a const object:

// print any type we don't otherwise handletemplate <typename T> string debug_rep(const T &t){    ostringstream ret; // see § 8.3 (p. 321)    ret << t; // uses T's output operator to print a representation of t    return ret.str(); // return a copy of the string to which ret is bound}

This function can be used to generate a string corresponding to an object of any type that has an output operator.