String To Lower/Upper in C++

Question

What is the best way people have found to do String to Lower case / Upper case in C++?

The issue is complicated by the fact that C++ isn\'t an English only programmi

Answer 1

For copy-pasters hoping to use Nic Strong's answer, note the spelling error in "use_factet" and the missing third parameter to std::transform:

locale loc("");
const ctype& ct = use_factet >(loc);
transform(str.begin(), str.end(), std::bind1st(std::mem_fun(&ctype::tolower), &ct));

should be

locale loc("");
const ctype& ct = use_facet >(loc);
transform(str.begin(), str.end(), str.begin(), std::bind1st(std::mem_fun(&ctype::tolower), &ct));