Question

I have a struct A that is defined as follows:

typedef struct A
{
    CvRect B; // rect 
    int C;
    double D;
}
A;

…

In my main program, I grab one item of a sequence of items:

    A *r = (A*) cvGetSeqElem(X, i);

Whenever I try to access rect, I get one of the following errors:

    if (r.rect.width>100 && r.rect.height>100)

error: request for member ‘rect’ in ‘r’, which is of non-class type ‘A’

or

    if (r->rect->width>100 && r->rect->height>100)

error: base operand of ‘->’ has non-pointer type ‘CvRect’

Any idea how to access the struct CvRect->height if it is inside another struct?

Thanks!

Answer 1

r is a pointer to `struct A, which contains a (non-pointer) member B (supposedly rect?) to a CvRect. So you have to write
r->rect.width