////
Copyright 2003-2017 Beman Dawes

Distributed under the Boost Software License, Version 1.0.

See accompanying file LICENSE_1_0.txt or copy at
http://www.boost.org/LICENSE_1_0.txt
////

[#history]
# History
:idprefix: history_

http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2006/n1975.html[N1975],
Filesystem Library Proposal for TR2, accepted for Library Technical
Report 2 (TR2) at the Berlin meeting, included additional components to
supplement the Standard Library's Diagnostics clause. Since then, these error
reporting components have received wider public scrutiny and enhancements have
been made to the design. The enhanced version has been used by
http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2006/n2054.pdf[N2054],
Networking  Library Proposal for TR2, demonstrating that these error reporting
components are useful beyond the original Filesystem Library.

The original proposal viewed error categories as a binary choice between
`errno` (i.e. POSIX-style) and the native operating system's error
codes. The proposed components now allow as many additional error categories as
are needed by either implementations or by users. The need to support additional
error categories, for example, occurs in some networking library implementations
because they are built on top of the POSIX `getaddrinfo` API that
uses error codes not based on `errno`.