[v3] Fix libstdc++/45228

[Paolo Carlini]

Hi,

tested x86_64-linux, committed to mainline. Maybe we can even better
here, but the cleanest solution I can see is adding constrains for
sizeof...(_UElements) == sizeof...(_Elements) to the converting
constructors and assignment operators of the primary template (something
that the FCD even encourages) and adding a quite short tuple
specialization for single element. That also allows to resolve the long
standing XXX fixme.

Paolo.
-------------- next part --------------
An embedded and charset-unspecified text was scrubbed...
Name: CL_45228
URL: <http://gcc.gnu.org/pipermail/libstdc++/attachments/20100810/6a8731df/attachment.ksh>
-------------- next part --------------
An embedded and charset-unspecified text was scrubbed...
Name: patch_45228
URL: <http://gcc.gnu.org/pipermail/libstdc++/attachments/20100810/6a8731df/attachment-0001.ksh>