> function<void()> i1(blub); //error: expected constructor, destructor, or type conversion before '<' token
> std::function<void()> i2(blub); //Compiles fine
> tr1::function<void()> i3(blub); //Compiles fine
> boost::function<void()> i4(blub); //Compiles fine

>What is wrong?

The same thing that is wrong with this:

namespace aspace{

    int i;

};

namespace bspace{

    int i;

};

using namespace aspace;

using namespace bspace;

int _tmain(int argc, _TCHAR* argv[]) {

    i = 0;

    return 0;

}