[libcxx-commits] [PATCH] D110497: [libc++][format][3/6] Adds a __container_buffer.

[Louis Dionne via Phabricator via libcxx-commits]

ldionne added inline comments.
Herald added a project: All.


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Comment at: libcxx/include/__format/buffer.h:168-175
+template <class _Container>
+concept __insertable =
+    same_as<_Container, typename _Container::__enable_format_insertable> &&
+    __formatter::__char_type<typename _Container::value_type> &&
+    requires(_Container& __t, typename _Container::value_type* __first,
+             typename _Container::value_type* __last) {
+  __t.insert(__t.end(), __first, __last);
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Is there any reason why this isn't implemented as a `bool` variable template that containers specialize or something similar? IMO it would be nice to keep containers free of a `__enable_format_insertable` typedef used for this sole purpose.

Requiring a specialization also makes it slightly less likely that users are going to do it for their own containers, which IMO is a good thing (we really don't want users to start depending on this unless the Standard commits to providing this functionality).

[Reading some other comments, I get the feeling this might have been how it was implemented in previous diffs, please let me know if that's the case]


Repository:
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  https://reviews.llvm.org/D110497/new/

https://reviews.llvm.org/D110497