Chapter 16. Introduction

The BoostBook documentation format is an extension of DocBook, an SGML- or XML-based format for describing documentation. BoostBook augments DocBook with semantic markup that aids in the documentation of C++ libraries, specifically the Boost C++ libraries, by providing the ability to express and refer to C++ constructs such as namespaces, classes, overloaded functions, templates, and specializations.

BoostBook offers additional features more specific to its use for documenting the Boost C++ libraries. These features are intended to eliminate or reduce the need for duplication of information and to aid in documenting portions of Boost that might otherwise not be documented. Examples of Boost-centric features include:

Testsuites: Testsuites in Boost are created by writing an appropriate Jamfile and including that Jamfile in status/Jamfile. If the testsuites are documented (as in the MultiArray library), the documentation is maintained separately from the testcase Jamfile, leading to duplication of information and the possibility of having the documentation out of sync with the Jamfile. BoostBook contains elements that describe a testsuite for both purposes: the BoostBook stylesheets can generate documentation for the testcases and also generate an appropriate Jamfile to integrate the testcases with the regression testing system.
Example programs: Example programs in documentation need to be duplicated in testcases to ensure that the examples compile and execute correctly. Keeping the two copies in sync is a tedious and error-prone task. For instance, the following code snippet persisted for six months:
```
std::cout << f(5, 3) >> std::endl;
```
The BoostBook format allows testcases to be generated by weaving together program fragments from example programs in the documentation. This capability is integrated with testsuite generation so that example programs are normal tests in BoostBook.