Re: [Boost-users] memory used by vector<int> vs vector<char>

If I create a vector<int> of 100 elements and a vector<char> of 100 elements, will there be any difference in the total memory used by them?

Yes, if sizeof(int)>sizeof(char) on your platform, then vector<int> consumes more memory than vector<char>, because the Standard requires that "the elements of a vector are stored contiguously, meaning that if v is a vector where T is some type other than bool, then it obeys the identity &v[n] == &v[0] + n for all 0 <= n < v.size()."

or which is more efficient?

What do you mean by saying "more efficient"? vector<char> consumes less memory, but accessing its elements might be less efficient on some platforms.