ISO/IEC TS 19568:2024

This document describes extensions to the C++ Standard Library (2). These extensions are classes and functions that are likely to be used widely within a program and/or on the interface boundaries between libraries written by different organizations.
It is intended that some of the library components be considered for standardization in a future version of C++. At present, they are not part of any C++ standard.
The goal of this document 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.