Thread: error C2079: 'CLASSA::objectb' uses undefined class 'CLASSB'

confuse about how that works, here, i would try to make it very clear,

Code:

// file 2
CLASS B
{
...
};

// file 1

CLASSB b; // forward declaration

CLASS A
{
...
B b; // error 
};

but...,
// file 1
CLASS A
{
...
B * b; // okey
};

so what i did is,

// file 1
CLASS B
{
...
};

CLASS A
{
...
B b; // now okey
};

why?? what was wrong there? what does the compiler mean by that? and why does the poitner version works?

many thanks!