Comment 2 for bug 1818157

Fixing is a good idea but maybe this is a 6 bug?

This appears to depend on isdigit() checking for the string end() position, which for C++11 is guaranteed to be the \0 character ([1] 21.4.1.5). There doesn't seem to be a way for the iterator to bypass this. But maybe I miss something here?

[1] http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2012/n3337.pdf