Commit Graph

12 Commits

Author SHA1 Message Date
Eric Fiselier a18ef6f1f9 Fix PR31916 - std::visit rejects visitors accepting lvalue arguments
A static assertion was misfiring since it checked
is_callable<Visitor, decltype(__variant_alt<T>.value)>. However
the decltype expression doesn't capture the value category as
required. This patch applies extra braces to decltype to fix
that.

llvm-svn: 294612
2017-02-09 19:01:22 +00:00
Eric Fiselier 46663d5567 Fix variant build errors with GCC 7
llvm-svn: 294141
2017-02-05 20:36:07 +00:00
Eric Fiselier f9127593a9 Implement P0513R0 - "Poisoning the Hash"
Summary:
Exactly what the title says.

This patch also adds a `std::hash<nullptr_t>` specialization in C++17, but it was not added by this paper and I can't find the actual paper that adds it.

See http://wg21.link/P0513R0 for more info.

If there are no comments in the next couple of days I'll commit this

Reviewers: mclow.lists, K-ballo, EricWF

Reviewed By: EricWF

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D28938

llvm-svn: 292684
2017-01-21 00:02:12 +00:00
Michael Park f4770ea983 Added a workaround for a `-fdelayed-template-parsing` bug.
Summary:
There seems to be an additional bug in `-fdelayed-template-parsing`
similar to
http://llvm.org/viewvc/llvm-project?view=revision&revision=236063.

This is a workaround for it for <variant> to compile with `clang-cl` on Windows.

Reviewers: EricWF

Differential Revision: https://reviews.llvm.org/D28734

llvm-svn: 292097
2017-01-16 08:14:25 +00:00
Eric Fiselier e2f2d1edef [NFC] Rename _LIBCPP_TYPE_VIS_ONLY to _LIBCPP_TEMPLATE_VIS
The name _LIBCPP_TYPE_VIS_ONLY is no longer accurate because both
_LIBCPP_TYPE_VIS and _LIBCPP_TYPE_VIS_ONLY expand to
__attribute__((__type_visibility__)) with Clang. The only remaining difference
is that _LIBCPP_TYPE_VIS_ONLY can be applied to templates whereas
_LIBCPP_TYPE_VIS cannot (due to dllimport/dllexport not being allowed on
templates).

This patch renames _LIBCPP_TYPE_VIS_ONLY to _LIBCPP_TEMPLATE_VIS.

llvm-svn: 291035
2017-01-04 23:56:00 +00:00
Saleem Abdulrasool 21711c451e remove some inherited attributes on exceptions
These exception types are marked with `_LIBCPP_EXCEPTION_ABI` which
expands to `__attribute__((__visibility__("default")))` or
`__declspec(dllexport)`.  When building for Windows, we would hit an
error:

    cannot apply 'dllexport' to a 'dllexport' class

Remove the duplicate annotations as they will be inherited from the
class.

llvm-svn: 290785
2016-12-31 17:34:26 +00:00
Eric Fiselier 02460bac8b Choose better hash values for std::monostate and valueless variants.
Previously these hashes were 0 and -1 respectively. These seem like common
sentinel values and should be avoided to prevent needless collisions.

This patch changes those values to different arbitrary numbers, which should
hopefully cause less collisions. Because I couldn't help myself I choose the
fundamental constants for gravity and the speed of light.

llvm-svn: 288623
2016-12-04 21:37:37 +00:00
Eric Fiselier 63322af698 Fix <variant> w/o exception support
llvm-svn: 288571
2016-12-03 01:58:07 +00:00
Eric Fiselier 5877920183 Fix C++03 build
llvm-svn: 288555
2016-12-02 23:41:18 +00:00
Eric Fiselier 918f32fc7b Make variant's index part of the hash value
llvm-svn: 288554
2016-12-02 23:38:31 +00:00
Eric Fiselier cb3ef1561d Fix generated warnings in <variant>
llvm-svn: 288552
2016-12-02 23:17:33 +00:00
Eric Fiselier 0d3d8de014 Implement C++17 <variant>. Patch from Michael Park!
This patch was reviewed as https://reviews.llvm.org/D23263.

llvm-svn: 288547
2016-12-02 23:00:05 +00:00