Thread: silly little error

Hello!!!!

I have a simple class - one constructor should take a parm of type std::vector<T>::iterator... but i get compilation errors.... any idea why?

im really stuck here, please help poor, poor little me
Cheers for any help!!




listed is the whole program...

Code:

#include <vector>


//
// Class MOO - doesn't do anyting
//
template <class T>
class MOO
{
public:
	MOO()
	{
	}


        // Im getting a compilation error on this line
	MOO(std::vector<T>::iterator m)
	{	
	}

	~MOO()
	{
	}
};

//
// Main function
//
int main()
{
	MOO<int> moo;
}

the compile error(s) are
error C2059: syntax error : ')'
error C2143: syntax error : missing ';' before '~'
error C2146: syntax error : missing ')' before identifier 'm'
error C2146: syntax error : missing ';' before identifier 'm'
error C2501: 'MOO<T>::m' : missing storage-class or type specifiers
error C2838: 'iterator' : illegal qualified name in member declaration
error C3254: 'MOO<T>' : class contains explicit override 'iterator' but does not derive from an interface that contains the function declaration
fatal error C1903: unable to recover from previous error(s); stopping compilation

I *think* this is where you need the typename keyword, like so:

Code:

MOO(typename std::vector<T>::iterator m)

Basically, because of templating, the compiler doesn't realize that std::vector<T> is a typename as opposed to a type.

I'm not an expert - just read a CUJ article on typename not to long ago. The reason, I think, is because of the additional scoping operator in there, and the way the compiler looks up names. It just has to have a nudge in that case, because it's looking for a concrete type of std::vector<T> which has a member named iterator. The typename keyword tells it that the whole mess (std::vector<T>::iterator) is a typename.

k makes sense... ill gooogle that document. Thanks so much.... thats 2 beers now.....