How Does the Regex Library Improve Your Programs?

• Brings support for regular expressions to C++

• Improves the robustness of input validation

Regular expressions are very often used in text processing. For example, there are a number of validation tasks that are suitable for regular expressions. Consider an application that requires the input to consist only of numbers. Another program might require a specific format, such as three digits, followed by a character, then two more digits. You could validate ZIP Codes, credit card numbers, Social Security numbers, or just about anything else; and using regular expressions to do the validation is straightforward. Another typical area where regular expressions excel are text substitutionsthat is, replacing some text with other text. Suppose you need to change the spelling of the word colour to color throughout a number of documents. Again, regular expressions provide the best means to do thatincluding remembering to make the changes also for Colour and COLOUR, and for the plural form colours, the verb colourize, and so forth. Yet another use case for regular expressions is in formatting of text.

Many popular programming languagesPerl is a prime examplehave built-in support for regular expressions, but that's not the case with C++. Also, the C++ Standard is silent when it comes to regexes. Boost.Regex is a very complete and effective library for incorporating regular expressions in C++ programs, and it even includes several different syntaxes that are used in widespread tools such as Perl, grep, and Emacs. It is one of the most renowned C++ libraries for working with regular expressions, and is both easy to use and incredibly powerful.