Question

Even after years C++ is confusing the hell out of me..
My class implements

virtual CStatCounter& operator= (CStatCounter const& inSC);

and

virtual CStatCounter operator+(const CStatCounter& rhs);

And I’m keeping a

vector<CStatCounter*> mStatistics 

somewhere else. Now all I’m trying to do is accumulate all values.
After being laughed at by std::accumulate I’ve switched to a simple loop rolled on my own, still no luck:

CStatCounter *iniCounter = new CStatCounter(0);
BOOST_FOREACH (CStatCounter *counter, mStatistics)
{
   iniCounter = iniCounter+counter;
}

The compiler (Xcode 4.2/clang) complains about

Invalid operands to binary expression ('CStatCounter *' and 'CStatCounter *')

I can change the loop body to counter+counter and it still fails with the same error message.

Shouldn’t it be smart enough to implicitly convert between references and pointers?
Am I missing something trivial here?

Answer 1

Shouldn’t it be smart enough to implicitly convert between references
and pointers?

It could, but that wouldn’t be C++, would it? When you can overload operators for every conceivable combination of operands, it’s really not safe to make such assumptions.

Am I missing something trivial here?

Dereferencing:

*iniCounter = *iniCounter + *counter;

By the way, you can still use std::accumulate, you just need a custom binary operation, like this:

CStatCounter MyAddFunc(const CStatCounter & lhs, const CStatCounter * rhsp)
{
    return lhs + *rhsp;
}

*iniCounter = std::accumulate(mStatistics.begin(), mStatistics.end(),
                              *iniCounter, MyAddFunc);