The type of the template is not "visible" by the compiler inside the lambda

Question

template<typename Wcf, typename Wdb>
void ComputeGenericDropCount(const function<void(Wdb *, int)> &func)
{
    Wcf::ForEach([&](Wcf *wcf) {
        Wdb *wdb = Wdb::Find(wcf->sourceId); // <--- ERROR
            // error C2653: 'Wdb' : is not a class or namespace name


        if(wdb)
            func(wdb, wcf->itemCount);
    });
}

It's weird, because it seems that "see" Wcfno problem, I even use it: wcf->itemCount.

Is there any workaround or reason why this is happening?

Answer 1

I don’t know why this is not working. But here is a workaround.

template<typename Wcf, typename Wdb>
void ComputeGenericDropCount(const function<void(Wdb *, int)> &func)
{
    auto my_find = Wdb::Find; // allows lambda to "capture" the correct function.
    Wcf::ForEach([&](Wcf *wcf) 
    {
        Wdb *wdb = my_find(wcf->sourceId);     

        if(wdb)
            func(wdb, wcf->itemCount);
    });
}