C++ STL vector iterators incompatible

Question

// Erase the missing items
vector::size_type StandardNum = FDRFreq.at(0).fData.size();
vector::iterator iter = FDRFreq.be         


        

Answer 1

Your code needs to become

while (iter != FDRFreq.end()){
    if( iter->fData.size() < StandardNum){
        iter = FDRFreq.erase(iter);
    }
    else{
        ++iter;
    }
}

"vector iterators incompatible" means that the iterator you're using has been invalidated - that is to say, there is no guarantee that the elements it points to still exist at that memory location. An erase of a vector element invalidates the iterators following that location. .erase returns a new, valid iterator you can use instead.

If you're new to STL, I highly recommend you read Scott Myer's Effective STL (and Effective C++, while you're at it)