unable to apply std::set_intersection on different types of structs with a common field

Question

I am trying to use use std::set_intersection to find common elements between 2 completely different types of data structures that have a common binding \'na

Answer 1

set_intersection isn't magic, if you have sorted vectors it is very easy to roll your own, roughly like this:

auto ta = aStructs.begin();
auto tb = bStructs.begin();
while( ta != aStructs.end() && tb != bStructs.end() ){
    if( ta->mCommonField < tb->mCommonField ){
        ++ta;
    } else if( tb->mCommonField < ta->mCommonField ){
        ++tb;
    } else {
        std::cout << "found common: " << ta->mCommonField << std::endl;
        ++ta;
        ++tb;
    }
}