C / C++ / MFC

// substitute comparator for char* that orders items
// more "reasonably" than regular lexical comparison.
// it uses embedded numbers like a person would.
struct MyLessC:binary_function<const char*,const char*,bool> {
    bool operator()(const char* a,const char* b) const {
        for (;; ) {
            if (*a>='0'&&*a<='9') {
                int _a=atoi(a);
                while(*a>='0'&&*a<='9')
                    ++a;
                if (*b>='0'&&*b<='9') {
                    int _b=atoi(b);
                    while(*b>='0'&&*b<='9')
                        ++b;
                    if (_a!=_b)
                        return _a<_b;
                } else {
                    return *b>'9';
                }
            } else if (*b>='0'&&*b<='9') {
                int _b=atoi(b);
                while(*b>='0'&&*b<='9')
                    ++b;
                return *a<'0';
            } else { // two chars
                if (*a!=*b)
                    return *a<*b;
                else if (*a)
                    ++a,++b;
                else
                    return false;
            }
        }
        return false;
    }
};