c++ - how to compare two vectors index by index contained by shared_ptr

Question

I have a two shared pointers to vector of strings: b_paras and b_paras_sig

I have traversed the loop for each, using range based for loop as follows:

for ( const std::string &para1 : *b_paras )

and

for ( const std::string &para2 : *b_paras_sig)

Now I want to compare the each element of these vectors, index by index and find out the mismatch.

I think nested loop may not fit as a solution here.

Is there any way to solve this?

Thanks in advance.

question from:https://stackoverflow.com/questions/65939223/how-to-compare-two-vectors-index-by-index-contained-by-shared-ptr

Answer 1

There's no elegant way to do that in C++, AFAIK.
Python has a handful zip() function to iterate over multiple sequences at once, and Boost has an equivalent: https://www.boost.org/doc/libs/1_75_0/libs/iterator/doc/zip_iterator.html

Otherwise just make something like

    for(auto it = std::make_pair(a->begin(), b->begin()); 
        it.first != a->end() && it.second != b->end();
        ++it.first, ++it.second) {
            if (*it.first != *it.second) return false;
        }
    }
    return true;