scope:

This Technical Report describes extensions to the C++ standard library that is described in the International Standard for the C++ programming language [14].

This Technical Report is non-normative. Some of the library components in this Technical Report may be considered for standardization in a future version of C++, but they are not currently part of any C++ standard. Some of the components in this Technical Report may never be standardized, and others may be standardized in a substantially changed form.

The goal of this Technical Report is to build more widespread existing practice for an expanded C++ standard library. It gives advice on extensions to those vendors who wish to provide them.

Relation to C++ Standard Library Introduction

Unless otherwise specified, the whole of the ISO C++ Standard Library introduction [lib.library] is included in this Technical Report by reference.

Categories of extensions [tr.intro.ext]

This Technical Report describes four general categories of library extensions:

1. New requirement tables, such as the regular expression traits requirements in 7.2. These are not directly expressed as software; they specify the circumstances under which user-written components will interoperate with the components described in this Technical Report.

2. New library components (types and functions) that are declared in entirely new headers, such as the class templates in the header (6.3.4.1).

3. New library components declared as additions to existing standard headers, such as the mathematical special functions added to the headers and in 5.2.1 and 5.2.2

4. Additions to standard library components, such as the extensions to class std::pair in 6.1.4.

2 New headers are distinguished from extensions to existing headers by the title of the synopsis clause. In the first case, the title is of the form "Header synopsis", and the synopsis includes all namespace scope declarations contained in the header. In the second case, the title is of the form "Additions to header synopsis" and the synopsis includes only the extensions, i.e. those namespace scope declarations that are not present in the C++ standard [14].