Question

What does this statement in C++ mean. I came across by reading about Typelists.

I don’t understand what the operator “>” stands for in typelist? I have never used this so far in C++ template stuff?

template 
struct typelist
{
    typedef H head;
    typedef T tail;
};


typedef typelist > >
    floating_point_types;

Thanks for some short explanations!
¿Is this variadic templates?

Answer 1

The code fragment looks wrong. From the names and the context I guess that it was meant to look like this:

template <typename H, typename T>
struct typelist
{
    typedef H head;
    typedef T tail;
};


typedef typelist<float, typelist<double, long double> >
    floating_point_types;

The original code likes as if it was pasted into a HTML document and, thus, had sequences of ‘<…>’ removed.

Of course, with C++ 2011 we wouldn’t need to do something like this. We could instead just use variadic templates:

template <typename... T> struct typelist {};

typedef typelist<float, double, long double> floating_point_types;