How do I deal with “signed/unsigned mismatch” warnings (C4018)?

I work with a lot of calculation code written in c++ with high-performance and low memory overhead in mind. It uses STL containers (mostly std::vector) a lot, and iterates over that containers almost in every single function.

The iterating code looks like this:

for (int i = 0; i < things.size(); ++i)
{
    // ...
}

But it produces the signed/unsigned mismatch warning (C4018 in Visual Studio).

Replacing int with some unsigned type is a problem because we frequently use OpenMP pragmas, and it requires the counter to be int.

I’m about to suppress the (hundreds of) warnings, but I’m afraid I’ve missed some elegant solution to the problem.

On iterators. I think iterators are great when applied in appropriate places. The code I’m working with will never change random-access containers into std::list or something (so iterating with int i is already container agnostic), and will always need the current index. And all the additional code you need to type (iterator itself and the index) just complicates matters and obfuscates the simplicity of the underlying code.

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