"implementation-defined" parts of the library

[Magnus Fromreide]

Two years ago Jonathan wrote and asked about the implementation-defined
parts of the library.

It seems that some parts of this now is documented but I failed to find
anything regarding the set of headers in a freestanding implementation.
What headers are available in a freestanding environment?

On Fri, 2011-05-06 at 20:22 +0100, Jonathan Wakely wrote:
> I've compiled the following list of implementation-defined parts of
> the standard library (there is also an index of implementation-defined
> behaviour in the FDIS).
> 
> We are required by [defns.impl.defined] to document our implementation
> defined behaviour, which we don't do for some (or most?) of the items
> below.
> 
> The G++ front end documents implementation-defined behaviour at
> http://gcc.gnu.org/onlinedocs/gcc/C_002b_002b-Implementation.html
> I think we should have a similar single place in our manual where we
> list all the choices, rather than scattering it around the manual.
> 
> I'm going to start documenting missing pieces but if someone else
> wants to help then I'd be grateful - it would be a great way to help
> the project and to become familiar with some of the internals of
> libstdc++ - volunteers would be very welcome!  If a few people want to
> help then I might create a wiki page so we can track what's been done
> and don't duplicate work, but for now just reply to this mail if you
> want to contribute some documentation.  Some of the items can be
> covered *very* simply, e.g. NULL is defined to be __null by this
> implementation. There, that was easy, eh? :^)
> 
> If any of the items below are already covered by the libstdc++ manual
> please point them out to me, to save me trawling around to see what
> we've documented already.  I know about
> http://gcc.gnu.org/onlinedocs/libstdc++/manual/support.html#std.support.types.null
> for NULL.
> 
> 
> [compliance]/2
> A freestanding implementation has an implementation-defined set of headers.

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