Previously __libcpp_is_constructible checked the validity of reference
construction using 'eat<To>(declval<From>())' but this doesn't consider
From's explicit conversion operators. This patch teaches __libcpp_is_constructible
how to handle these cases. To do this we need to check the validity
using 'static_cast<To>(declval<From>())'. Unfortunately static_cast allows
additional base-to-derived and lvalue-to-rvalue conversions, which have to be
checked for and manually rejected.
While implementing these changes I discovered that Clang incorrectly
rejects `static_cast<int&&>(declval<float&>())` even though
`int &&X(declval<float&>())` is well formed. In order to tolerate this bug
the `__eat<T>(...)` needs to be left in-place. Otherwise it could be replaced
entirely with the new static_cast implementation.
Thanks to Walter Brown for providing the test cases.
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@285786 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Adapt implementation of Library Fundamentals TS optional into an implementation of N4606 optional.
- Update relational operators per http://wg21.link/P0307
- Update to requirements of http://wg21.link/P0032
- Extension: Implement trivial copy/move construction/assignment for `optional<T>` when `T` is trivially copyable.
Audit P/Rs for optional LWG issues:
- 2756 "C++ WP optional<T> should 'forward' T's implicit conversions" Implemented, which also resolves 2753 "Optional's constructors and assignments need constraints" (modulo my refusal to explicitly delete the move operations, which is a design error that I'm working on correcting in the 2756 P/R).
- 2736 "nullopt_t insufficiently constrained" Already conforming. I've added a test ensuring that `nullopt_t` is not copy-initializable from an empty braced-init-list, which I believe is the root intent of the issue, to avoid regression.
- 2740 "constexpr optional<T>::operator->" Already conforming.
- 2746 "Inconsistency between requirements for emplace between optional and variant" No P/R, but note that the author's '"suggested resolution" is already implemented.
- 2748 "swappable traits for optionals" Already conforming.
- 2753 "Optional's constructors and assignments need constraints" Implemented.
Most of the work for this patch was done by Casey Carter @ Microsoft. Thank you Casey!
Reviewers: mclow.lists, CaseyCarter, EricWF
Differential Revision: https://reviews.llvm.org/D22741
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@283980 91177308-0d34-0410-b5e6-96231b3b80d8
This patch is largely thanks to Casey Carter @ Microsoft. He did the initial
work of porting our experimental implementation and tests over to namespace
std.
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@283977 91177308-0d34-0410-b5e6-96231b3b80d8
There is a bug in Clang's __is_constructible builtin that causes it
to return true for function types; ex [T = void()].
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@276092 91177308-0d34-0410-b5e6-96231b3b80d8
The previous implementation relied highly on specializations to handle
special cases. This new implementation lets the compiler do the work when possible.
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@276084 91177308-0d34-0410-b5e6-96231b3b80d8
Quite a few libcxx tests seem to follow the format:
#if _LIBCPP_STD_VER > X
// Do test.
#else
// Empty test.
#endif
We should instead use the UNSUPPORTED lit directive to exclude the test on
earlier C++ standards. This gives us a more accurate number of test passes
for those standards and avoids unnecessary conflicts with other lit
directives on the same tests.
Reviewers: bcraig, ericwf, mclow.lists
Differential revision: http://reviews.llvm.org/D20730
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@271108 91177308-0d34-0410-b5e6-96231b3b80d8
This patch does the following:
* Remove <__config> includes from some container tests.
* Guards uses of std::launch::any in async tests because it's an extension.
* Move "test/std/extensions" to "test/libcxx/extensions"
* Moves various non-standard tests including those in "sequences/vector",
"std/localization" and "utilities/meta".
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@267981 91177308-0d34-0410-b5e6-96231b3b80d8
The primary purpose of this patch is to add the 'is_callable' traits.
Since 'is_nothrow_callable' required making 'INVOKE' conditionally noexcept
I also took this oppertunity to implement a constexpr version of INVOKE.
This fixes 'std::experimental::apply' which required constexpr 'INVOKE support'.
This patch will be followed up with some cleanup. Primarly removing most
of "__member_function_traits" since it's no longer used by INVOKE (in C++11 at least).
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@266836 91177308-0d34-0410-b5e6-96231b3b80d8
Since they're scheduled to be updated soon, we'll just comment out this test for
the moment, and re-commit when the bots are updated.
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@261661 91177308-0d34-0410-b5e6-96231b3b80d8
This patch goes through and enables C++11 and C++14 features for newer GCC's.
The main changes are:
1. Turn on variable templates. (Uses __cpp_variable_templates)
2. Assert atomic<Tp> is trivially copyable (Uses _GNUC_VER >= 501).
3. Turn on trailing return support for GCC. (Uses _GNUC_VER >= 404)
4. XFAIL void_t test for GCC 5.1 and 5.2. Fixed in GCC 6.
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@255585 91177308-0d34-0410-b5e6-96231b3b80d8
