gcc/libstdc++-v3

file: libstdc++-v3/README

New users may wish to point their web browsers to the file documentation.html
in the 'docs/html' subdirectory.  It contains brief building instructions and
notes on how to configure the library in interesting ways.

Instructions for configuring and building appear in
docs/html/install.html.

This directory contains the files needed to create an ISO Standard C++
Library.

It has subdirectories:

  docs
     Files in HTML and text format that document usage, quirks of the
     implementation, and contributor checklists.

  include/std
     Files meant to be found by #include <name> directives in
     standard-conforming user programs.  

  include/c
     Headers intended to directly include standard C headers. 
     [NB: this can be enabled via --enable-cheaders=c]

  include/c_std
     Headers intended to include standard C headers, and put select
     names into the std:: namespace.
     [NB: this is the default, and is the same as --enable-cheaders=c_std]

  include/c_shadow
     Headers intended to shadow standard C headers provided by an
     underlying OS or C library, and other headers depended on directly
     by C++ headers (e.g. unistd.h).  These are meant to wrap the names
     defined there into the _C_legacy namespace.
     [NB: this can be enabled via --enable-cheaders=c_shadow]

  include/bits
     Files included by standard headers and by other files in
     the bits directory.  Includes a set of files bits/std_xxxx.h
     that implement the standard headers <xxxx>.

  include/backward
     Headers provided for backward compatibility, such as <iostream.h>.
     They are not used in this library.

  include/ext
     Headers that define extensions to the standard library.  No
     standard header refers to any of them.

  src
     Files that are used in constructing the library, but are not
     installed.

  testsuites/17_* to 27_*
     Test programs are here, and may be used to begin to exercise the 
     library.  Support for "make check" and "make check-install" is
     complete, and runs through all the subdirectories here when this
     command is issued from the build directory.  Please note that
     "make check" requires DejaGNU 1.4 or later to be installed.  Please
     note that "make check-script" calls the script mkcheck, which
     requires bash, and which may need the paths to bash adjusted to
     work properly, as /bin/bash is assumed.

Other subdirectories contain variant versions of certain files
that are meant to be copied or linked by the configure script.
Currently these are:

  config/cpu
  config/os
  config/io
  config/locale

In addition, three subdirectories are convenience libraries:

  libio
     Contains the subset of the GNU libio library needed for
     C++. Currently not used.

  libmath
     Support routines needed for C++ math. Only needed if the
     underlying "C" implementation is weak or looses.

  libsupc++
     Contains the runtime library for C++, including exception
     handling and memory allocation and deallocation, RTTI, terminate
     handlers, etc.

Note that glibc also has a bits/ subdirectory.  We will either
need to be careful not to collide with names in its bits/
directory; or rename bits to (e.g.) cppbits/.

In files throughout the system, lines marked with an "XXX" indicate
a bug or incompletely-implemented feature.  Lines marked "XXX MT"
indicate a place that may require attention for multi-thread safety.