[PATCH] libstdc++: Add missing bits of P0896R4 pertaining to [back|front]_insert_iterator

[Jonathan Wakely]

This should do the same changes for std::insert_iterator, but it
currently crashes the compiler (PR 93907). I am not committing this
yet.


-------------- next part --------------
A non-text attachment was scrubbed...
Name: patch.txt
Type: text/x-patch
Size: 10778 bytes
Desc: not available
URL: <http://gcc.gnu.org/pipermail/libstdc++/attachments/20200224/a2a356df/attachment.bin>