[Patch] Add __versa_string to mainline/ext

[Paolo Carlini]

Hi everyone,

the below finally adds to mainline/ext the "modular" string framework:
in this incarnation, as an extension, I'm adding a 4th template argument
(see vstring.h and vstring_fwd.h), thus making easy testing and
comparing the available base classes.

Actually the work proceeded rather smoothly and you will find also the
I/O bits, in a basic version (no performance optimizations for
char/wchar_t exploiting protected members of streambuf).

For now, I'm only adding an handful of instantation testcases, but I'm
fairly confident that the code would also pass a full testsuite (modulo
trivial fixes like typos) because the classes are adapted from v7-branch
without substantive changes besides renamings, reformattings and other
very-very simple things. More testing during the next days, anyway. Then
I'd like to commit the patch and proceed with further improvements.

Paolo.

P.S. I considered creating a specific directory under /ext but seems
overkill for so few files. Also, both comments at the beginning of the
files and the file names themselves should make sufficiently clear the
purpose of each new file.

//////////////
-------------- next part --------------
An embedded and charset-unspecified text was scrubbed...
Name: CL_vstring
URL: <http://gcc.gnu.org/pipermail/libstdc++/attachments/20050703/5723ab92/attachment.ksh>
-------------- next part --------------
An embedded and charset-unspecified text was scrubbed...
Name: patch_vstring
URL: <http://gcc.gnu.org/pipermail/libstdc++/attachments/20050703/5723ab92/attachment-0001.ksh>