Standard Library Header Files
The interface to the C++ Standard Library consists of 78 header files, 26 of which present the C standard library. It’s often difficult to remember which header files you need to include in your source code, so this material provides a brief description of the contents of each header, organized into eight categories:
- The C Standard Library
- Algorithms, iterators, and allocators
- General utilities
- Mathematical utilities
- I/O Streams
- Threading library
THE C STANDARD LIBRARY
The C++ Standard Library includes the entire C Standard Library. The header files are generally the same, except for two points:
- The header names are <cname> instead of <name.h>.
- All the names declared in the header files are in the std namespace.
For backward compatibility, you can still include <name.h> if you want. However, that puts the names into the global namespace instead of the std namespace. We recommend avoiding this feature.
The following table provides a summary of the most useful functionality:
|HEADER FILE NAME||CONTENTS|
|<ccomplex>||Utilities to work with complex numbers.|
|<cctype>||Character predicates and manipulation functions, such as isspace() and tolower().|
|<cerrno>||Defines errno expression. ...|