The Boost C++ Libraries
The following libraries provide tools to simplify working with strings.
Boost.StringAlgorithms defines many algorithms specifically for strings. For example, you will find algorithms to convert strings to lower or upper case.
Boost.LexicalCast provides a cast operator to convert a number to a string or vice versa. The library uses stringstreams internally but might be optimized for conversions between certain types.
Boost.Format provides a type-safe alternative for std::printf(). Like Boost.LexicalCast, this library uses stringstreams internally. Boost.Format is extensible and supports user-defined types if output stream operators are defined.
Boost.Regex and Boost.Xpressive are libraries to search within strings with regular expressions. While Boost.Regex expects regular expressions written as strings, Boost.Xpressive lets you write them as C++ code.
Boost.Tokenizer makes it possible to iterate over substrings in a string.
Boost.Spirit can be used to develop parsers based on rules similar to Extended Backus-Naur-Form.