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| author | Tim Shen <timshen@google.com> | 2016-11-27 00:32:04 +0000 |
|---|---|---|
| committer | Tim Shen <timshen@gcc.gnu.org> | 2016-11-27 00:32:04 +0000 |
| commit | 3203ed5f0182e7dbf1c74e6598e718641a3d4013 (patch) | |
| tree | 0db3aa4bf197b8f1448c76a2cd58777ba299b74b /libstdc++-v3 | |
| parent | 216c1ee8384255ff0a345608d0f97e74b2da312c (diff) | |
| download | gcc-3203ed5f0182e7dbf1c74e6598e718641a3d4013.zip gcc-3203ed5f0182e7dbf1c74e6598e718641a3d4013.tar.gz gcc-3203ed5f0182e7dbf1c74e6598e718641a3d4013.tar.bz2 | |
re PR libstdc++/78441 ([variant] variant_alternative doesn't allow cv qualifiers)
PR libstdc++/78441
* include/std/variant: Propagate cv qualifications to types returned
by variant_alternative.
* testsuite/20_util/variant/compile.cc: Tests.
From-SVN: r242892
Diffstat (limited to 'libstdc++-v3')
| -rw-r--r-- | libstdc++-v3/ChangeLog | 7 | ||||
| -rw-r--r-- | libstdc++-v3/include/std/variant | 12 | ||||
| -rw-r--r-- | libstdc++-v3/testsuite/20_util/variant/compile.cc | 9 |
3 files changed, 28 insertions, 0 deletions
diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog index d663f70..4a26191 100644 --- a/libstdc++-v3/ChangeLog +++ b/libstdc++-v3/ChangeLog @@ -1,3 +1,10 @@ +2016-11-26 Tim Shen <timshen@google.com> + + PR libstdc++/78441 + * include/std/variant: Propagate cv qualifications to types returned + by variant_alternative. + * testsuite/20_util/variant/compile.cc: Tests. + 2016-11-23 Felix Morgner <felix.morgner@gmail.com> Jonathan Wakely <jwakely@redhat.com> diff --git a/libstdc++-v3/include/std/variant b/libstdc++-v3/include/std/variant index 7d93575..34ad3fd 100644 --- a/libstdc++-v3/include/std/variant +++ b/libstdc++-v3/include/std/variant @@ -85,6 +85,18 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION using variant_alternative_t = typename variant_alternative<_Np, _Variant>::type; + template<size_t _Np, typename _Variant> + struct variant_alternative<_Np, const _Variant> + { using type = add_const_t<variant_alternative_t<_Np, _Variant>>; }; + + template<size_t _Np, typename _Variant> + struct variant_alternative<_Np, volatile _Variant> + { using type = add_volatile_t<variant_alternative_t<_Np, _Variant>>; }; + + template<size_t _Np, typename _Variant> + struct variant_alternative<_Np, const volatile _Variant> + { using type = add_cv_t<variant_alternative_t<_Np, _Variant>>; }; + constexpr size_t variant_npos = -1; _GLIBCXX_END_NAMESPACE_VERSION diff --git a/libstdc++-v3/testsuite/20_util/variant/compile.cc b/libstdc++-v3/testsuite/20_util/variant/compile.cc index 2470bcc..e3330be 100644 --- a/libstdc++-v3/testsuite/20_util/variant/compile.cc +++ b/libstdc++-v3/testsuite/20_util/variant/compile.cc @@ -330,3 +330,12 @@ void test_adl() variant<X> v8{allocator_arg, a, in_place_type<X>, il, x}; variant<X> v9{allocator_arg, a, in_place_type<X>, 1}; } + +void test_variant_alternative() { + static_assert(is_same_v<variant_alternative_t<0, variant<int, string>>, int>, ""); + static_assert(is_same_v<variant_alternative_t<1, variant<int, string>>, string>, ""); + + static_assert(is_same_v<variant_alternative_t<0, const variant<int>>, const int>, ""); + static_assert(is_same_v<variant_alternative_t<0, volatile variant<int>>, volatile int>, ""); + static_assert(is_same_v<variant_alternative_t<0, const volatile variant<int>>, const volatile int>, ""); +} |