C++ Technical Report 1

C++ Technical Report 1 (TR1) is the common name for ISO/IEC TR 19768, C++ Library Extensions, which was a document proposing additions to the C++ standard library for the C++03 language standard. The additions include regular expressions, smart pointers, hash tables, and random number generators. TR1 was not a standard itself, but rather a draft document. However, most of its proposals became part of the later official standard, C++11. Before C++11 was standardized, vendors used this document as a guide to create extensions. The report's goal was "to build more widespread existing practice for an expanded C++ standard library."

The report was first circulated in draft form in 2005 as Draft Technical Report on C++ Library Extensions, then published in 2007 as an ISO/IEC standard as ISO/IEC TR 19768:2007.

Compilers did not need to include the TR1 components in order to conform to the C++ standard, because TR1 proposals were not part of the standard itself, only a set of possible additions that were still to be ratified. However, most of TR1 was available from Boost, and several compiler/library distributors implemented all or some of the components. TR1 is not the complete list of additions to the library that appeared in C++11. For example, C++11 includes a thread support library that is not available in TR1.

The new components were defined in the std::tr1 namespace to distinguish them from the then-current standard library.

There is also a second technical report, C++ Technical Report 2, planned to be published after C++11.

TR1 includes the following components:

Reference wrapper – enables passing references, rather than copies, into algorithms or function objects. The feature was based on Boost.Ref. A wrapper reference is obtained from an instance of the template class reference_wrapper. Wrapper references are similar to normal references (‘&’) of the C++ language. To obtain a wrapper reference from any object the template class ref is used (for a constant reference cref is used).

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