c++templatesdefault-valuedefault-arguments

How to specify a default function argument with a template parameter type T

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;
}
Solution

  • 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.