3 Commits

Author SHA1 Message Date
Christopher Di Bella
e9ef45635b [clang] adds unary type transformations as compiler built-ins
Adds

* `__add_lvalue_reference`
* `__add_pointer`
* `__add_rvalue_reference`
* `__decay`
* `__make_signed`
* `__make_unsigned`
* `__remove_all_extents`
* `__remove_extent`
* `__remove_const`
* `__remove_volatile`
* `__remove_cv`
* `__remove_pointer`
* `__remove_reference`
* `__remove_cvref`

These are all compiler built-in equivalents of the unary type traits
found in [[meta.trans]][1]. The compiler already has all of the
information it needs to answer these transformations, so we can skip
needing to make partial specialisations in standard library
implementations (we already do this for a lot of the query traits). This
will hopefully improve compile times, as we won't need use as much
memory in such a base part of the standard library.

[1]: http://wg21.link/meta.trans

Co-authored-by: zoecarver

Reviewed By: aaron.ballman, rsmith

Differential Revision: https://reviews.llvm.org/D116203
2022-08-22 03:03:32 +00:00
Nico Weber
aacf1a9742 Revert "[clang] adds unary type transformations as compiler built-ins"
This reverts commit bc60cf2368de90918719dc7e3d7c63a72cc007ad.
Doesn't build on Windows and breaks gcc 9 build, see
https://reviews.llvm.org/D116203#3722094 and
https://reviews.llvm.org/D116203#3722128

Also revert two follow-ups. One fixed a warning added in
bc60cf2368de90918719dc7e3d7c63a72cc007ad, the other
makes use of the feature added in bc60cf2368de90918719dc7e3d7c63a72cc007ad
in libc++:

Revert "[libcxx][NFC] utilises compiler builtins for unary transform type-traits"
This reverts commit 06a1d917ef1f507aaa2f6891bb654696c866ea3a.

Revert "[Sema] Fix a warning"
This reverts commit c85abbe879ef3257de4db862ce249b060cc3d2a4.
2022-08-14 15:58:21 -04:00
Christopher Di Bella
bc60cf2368 [clang] adds unary type transformations as compiler built-ins
Adds

* `__add_lvalue_reference`
* `__add_pointer`
* `__add_rvalue_reference`
* `__decay`
* `__make_signed`
* `__make_unsigned`
* `__remove_all_extents`
* `__remove_extent`
* `__remove_const`
* `__remove_volatile`
* `__remove_cv`
* `__remove_pointer`
* `__remove_reference`
* `__remove_cvref`

These are all compiler built-in equivalents of the unary type traits
found in [[meta.trans]][1]. The compiler already has all of the
information it needs to answer these transformations, so we can skip
needing to make partial specialisations in standard library
implementations (we already do this for a lot of the query traits). This
will hopefully improve compile times, as we won't need use as much
memory in such a base part of the standard library.

[1]: http://wg21.link/meta.trans

Co-authored-by: zoecarver

Reviewed By: aaron.ballman, rsmith

Differential Revision: https://reviews.llvm.org/D116203
2022-08-14 17:12:15 +00:00