Question

If I typedef some type within a struct (functor), is the scope of the typedef local to the struct?

Consider the following example where I have typdef’ed foo to be an int and a double in the two separate functors. Is this example correct?

template <typename T> 
struct firstfunctor 
{ 
  typedef int foo; 

  foo operator()(const foo& a, const foo& b) 
  { 
    return /*whatever*/
  } 
}; 

template <typename T> 
struct secondfunctor 
{ 
  typedef double foo; 

  foo operator()(const foo& a, const foo& b) 
  { 
    return /*whatever*/
  } 
}; 

Answer 1

Yes, typedefs are scoped, and you define the member types firstfunctor::foo and secondfunctor::foo, respectively.