Vowels

This was in response to a question on Stackoverflow regarding a C++ question finding the number of unique vowels in a string.

Obviously the easiest I can think of is std::string("aeiou").find(c) != std::string::npos; - which admittedly a couple of people present - but I wanted to do something slightly different.

This is what I came up with.

http://stackoverflow.com/questions/21627999/write-a-c-program-that-finds-the-number-of-vowels-used-in-an-string