Question

Is it possible to define the default value for variables of a template function in C++?

Something like below:

template<class T> T sum(T a, T b, T c=????)
{
     return a + b + c;
}

Answer 1

Try this:

template<class T> T sum(T a, T b, T c=T())
{
     return a + b + c;
}

You can also put in T(5) if you are expecting an integral type and want the default value to be 5.