Implement LWG issue 2301: Mark std::tie as constexpr
llvm-svn: 202158
Cr-Mirrored-From: sso://chromium.googlesource.com/_direct/external/github.com/llvm/llvm-project
Cr-Mirrored-Commit: 0d1560e10e79f2d75a8fe09b07e40218d84f0ae5
diff --git a/include/tuple b/include/tuple
index 24e086d..30a958a 100644
--- a/include/tuple
+++ b/include/tuple
@@ -74,7 +74,7 @@
template <class... T> tuple<V...> make_tuple(T&&...); // constexpr in C++14
template <class... T> tuple<ATypes...> forward_as_tuple(T&&...) noexcept; // constexpr in C++14
-template <class... T> tuple<T&...> tie(T&...) noexcept;
+template <class... T> tuple<T&...> tie(T&...) noexcept; // constexpr in C++14
template <class... Tuples> tuple<CTypes...> tuple_cat(Tuples&&... tpls); // constexpr in C++14
// 20.4.1.4, tuple helper classes:
@@ -796,7 +796,7 @@
// tie
template <class ..._Tp>
-inline _LIBCPP_INLINE_VISIBILITY
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
tuple<_Tp&...>
tie(_Tp&... __t) _NOEXCEPT
{
diff --git a/test/utilities/tuple/tuple.tuple/tuple.creation/tie.pass.cpp b/test/utilities/tuple/tuple.tuple/tuple.creation/tie.pass.cpp
index 112ee39..e6ebf95 100644
--- a/test/utilities/tuple/tuple.tuple/tuple.creation/tie.pass.cpp
+++ b/test/utilities/tuple/tuple.tuple/tuple.creation/tie.pass.cpp
@@ -27,4 +27,13 @@
assert(i == 42);
assert(s == "C++");
}
+#if _LIBCPP_STD_VER > 11
+ {
+ static constexpr int i = 42;
+ static constexpr double f = 1.1;
+ constexpr std::tuple<const int &, const double &> t = std::tie(i, f);
+ static_assert ( std::get<0>(t) == 42, "" );
+ static_assert ( std::get<1>(t) == 1.1, "" );
+ }
+#endif
}
diff --git a/www/cxx1y_status.html b/www/cxx1y_status.html
index bb99d19..2ac2ad2 100644
--- a/www/cxx1y_status.html
+++ b/www/cxx1y_status.html
@@ -240,7 +240,7 @@
<tr><td><a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#2258">2258</a></td><td>a.erase(q1, q2) unable to directly return q2</td><td>Issaquah</td><td>Complete</td></tr>
<tr><td><a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#2263">2263</a></td><td>Comparing iterators and allocator pointers with different const-character</td><td>Issaquah</td><td></td></tr>
<tr><td><a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#2293">2293</a></td><td>Wrong facet used by num_put::do_put</td><td>Issaquah</td><td>Complete</td></tr>
- <tr><td><a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#2301">2301</a></td><td>Why is std::tie not constexpr?</td><td>Issaquah</td><td></td></tr>
+ <tr><td><a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#2301">2301</a></td><td>Why is std::tie not constexpr?</td><td>Issaquah</td><td>Complete</td></tr>
<tr><td><a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#2304">2304</a></td><td>Complexity of count in unordered associative containers</td><td>Issaquah</td><td>Complete</td></tr>
<tr><td><a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#2306">2306</a></td><td>match_results::reference should be value_type&, not const value_type&</td><td>Issaquah</td><td></td></tr>
<tr><td><a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#2308">2308</a></td><td>Clarify container destructor requirements w.r.t. std::array</td><td>Issaquah</td><td>Complete</td></tr>