Question

The following code:

#include <vector>
#include <algorithm>

struct myStructDim
{
    int     nId;
    int     dwHeight;
    int     dwWidth;
};    

void main()
{
    ::std::vector<myStructDim>  m_vec_dim;

    ::std::sort(m_vec_dim.begin(), m_vec_dim.end());
    m_vec_dim.erase(
        ::std::unique(m_vec_dim.begin(), m_vec_dim.end()),
        m_vec_dim.end()
        );
}

will not compile with many errors, such as:

error C2784: ‘bool std::operator
==(const std::vector<_Ty,_Alloc> &,const std::vector<_Ty,_Alloc> &)’ :
could not deduce template argument for
‘const std::vector<_Ty,_Alloc> &’ from
‘myStructDim’

I understand that I have to override an operator or two.

Which ones and how exactly please?

Thanks for the support!

Answer 1

You need comparison operators to express the “less-than” and “equality” relationships. Defining stand-alone boolean functions operator< and operator== that take two arguments, each const myStructDim&, and perform the comparison exactly the way you require, is probably simpler than defining then as methods within the struct.