ommand line interpreters, HTTP requests, and SMS messages are only a few of the applications in which different letter cases merely cause noise. To overcome this problem, such applications usually convert all strings to uppercase before any further processing.
Sadly, most of these apps use C-style strings and ad-hoc, in-house conversion routines that more often than not suffer from bugs, illegibility, and performance overhead. The std::string class provides more than a hundred member functions and overloaded operators. Yet, none of these functions transforms a string to uppercase or lowercase letters.
Use the STL transform() algorithm to change a string's case easily.