What's the best strategy to get rid of “warning C4267 possible loss of data”?

Question

I ported some legacy code from win32 to win64. Not because the win32 object size was too small for our needs, but just because win64 is more standard now and we wish to port all

Answer 1

Use the correct type (option 2) - the function/interface defines that type for you, use it.

std::size_t size = v.size(); // given vector<>::size_type is size_t
// or a more verbose
decltype(v)::size_type size = v.size();

It goes to the intent... you are getting the size of v and that size has a type. If the correct type had been used from the beginning, this would not have been a problem.

If you require that value later as another type, transform it then; the safe_cast<> is then a good alternative that includes the runtime bounds checking.

Option 6. Use auto

When you use size = v.size(), if you are not concerned what the type is, only that you use the correct type,

auto size = v.size();

And let the compiler do the hard work for you.