[committed 3/3] libstdc++: Fix constraints on std::expected<void, E> constructor [PR105153]
Jonathan Wakely
jwakely@redhat.com
Fri Apr 8 17:38:06 GMT 2022
Tested x86_64-linux, pushed to trunk.
-- >8 --
libstdc++-v3/ChangeLog:
PR libstdc++/105153
* include/std/expected
(expected<void,E>::expected(expected<U,G>&&)): Fix constraints.
* testsuite/20_util/expected/cons.cc: Check constructor.
---
libstdc++-v3/include/std/expected | 4 ++--
.../testsuite/20_util/expected/cons.cc | 18 ++++++++++++++++++
2 files changed, 20 insertions(+), 2 deletions(-)
diff --git a/libstdc++-v3/include/std/expected b/libstdc++-v3/include/std/expected
index 1864e866ed0..3446d6dbaed 100644
--- a/libstdc++-v3/include/std/expected
+++ b/libstdc++-v3/include/std/expected
@@ -966,8 +966,8 @@ namespace __expected
}
template<typename _Up, typename _Gr>
- requires is_void_v<_Tp>
- && is_constructible_v<_Er, const _Gr&>
+ requires is_void_v<_Up>
+ && is_constructible_v<_Er, _Gr>
&& (!__cons_from_expected<_Up, _Gr>)
constexpr explicit(!is_convertible_v<_Gr, _Er>)
expected(expected<_Up, _Gr>&& __x)
diff --git a/libstdc++-v3/testsuite/20_util/expected/cons.cc b/libstdc++-v3/testsuite/20_util/expected/cons.cc
index 1fe5b7bf4d1..6946858198c 100644
--- a/libstdc++-v3/testsuite/20_util/expected/cons.cc
+++ b/libstdc++-v3/testsuite/20_util/expected/cons.cc
@@ -162,6 +162,22 @@ test_copy()
return true;
}
+constexpr bool
+test_pr105153()
+{
+ struct E {
+ E(int&&) = delete;
+ E(const int&);
+ };
+
+ std::expected<void, E> e(std::expected<void, int>{});
+
+ static_assert( ! std::is_constructible_v<std::expected<void, int>,
+ std::expected<int, int>> );
+
+ return true;
+}
+
int main()
{
test_default();
@@ -172,4 +188,6 @@ int main()
static_assert( test_err() );
test_copy();
static_assert( test_copy() );
+ test_pr105153();
+ static_assert( test_pr105153() );
}
--
2.34.1
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