Tested x86_64-linux. Pushed to trunk.
-- >8 --
This was approved at the C++ meeting in February.
libstdc++-v3/ChangeLog:
* include/bits/regex.h (sub_match::swap): New function.
* testsuite/28_regex/sub_match/lwg3204.cc: New test.
---
libstdc++-v3/include/bits/regex.h | 10 +++++
.../testsuite/28_regex/sub_match/lwg3204.cc | 38 +++++++++++++++++++
2 files changed, 48 insertions(+)
create mode 100644 libstdc++-v3/testsuite/28_regex/sub_match/lwg3204.cc
diff --git a/libstdc++-v3/include/bits/regex.h
b/libstdc++-v3/include/bits/regex.h
index 79903fad1e5..26ac6a21c31 100644
--- a/libstdc++-v3/include/bits/regex.h
+++ b/libstdc++-v3/include/bits/regex.h
@@ -1006,6 +1006,16 @@ _GLIBCXX_BEGIN_NAMESPACE_CXX11
{ return this->_M_str().compare({__s, __n}); }
/// @endcond
+ // _GLIBCXX_RESOLVE_LIB_DEFECTS
+ // 3204. sub_match::swap only swaps the base class
+ /// Swap the values of two sub_match objects.
+ void
+ swap(sub_match& __s) noexcept(__is_nothrow_swappable<_BiIter>::value)
+ {
+ this->pair<_BiIter, _BiIter>::swap(__s);
+ std::swap(matched, __s.matched);
+ }
+
private:
// Simplified basic_string_view for C++11
struct __string_view
diff --git a/libstdc++-v3/testsuite/28_regex/sub_match/lwg3204.cc
b/libstdc++-v3/testsuite/28_regex/sub_match/lwg3204.cc
new file mode 100644
index 00000000000..58ef0df58a1
--- /dev/null
+++ b/libstdc++-v3/testsuite/28_regex/sub_match/lwg3204.cc
@@ -0,0 +1,38 @@
+// { dg-do run { target c++11 } }
+#include <regex>
+#include <testsuite_hooks.h>
+
+// LWG 3204. sub_match::swap only swaps the base class
+
+int main()
+{
+ std::sub_match<const char*> a, b;
+ a.matched = true;
+ a.swap(b);
+ VERIFY( ! a.matched );
+ VERIFY( b.matched );
+}
+
+struct iter
+{
+ using value_type = char;
+ using difference_type = long;
+ using pointer = const char*;
+ using reference = const char&;
+ using iterator_category = std::bidirectional_iterator_tag;
+
+ iter();
+ iter(const iter&) noexcept(false);
+
+ iter& operator++();
+ iter operator++(int);
+ iter& operator--();
+ iter operator--(int);
+ reference operator*() const;
+ pointer operator->() const;
+};
+
+using CS = std::csub_match;
+static_assert( noexcept(std::declval<CS&>().swap(std::declval<CS&>())) );
+using IS = std::sub_match<iter>;
+static_assert( ! noexcept(std::declval<IS&>().swap(std::declval<IS&>())) );
--
2.39.2
