Fix PR33727: std::basic_stringbuf only works with DefaultConstructible allocators. Thanks to Jonathan Wakely for the report and suggested fix git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@309838 91177308-0d34-0410-b5e6-96231b3b80d8 
diff --git a/include/sstream b/include/sstream index b9903f9..fe65fd7 100644 --- a/include/sstream +++ b/include/sstream 
@@ -249,7 +249,8 @@  template <class _CharT, class _Traits, class _Allocator>  basic_stringbuf<_CharT, _Traits, _Allocator>::basic_stringbuf(const string_type& __s,  ios_base::openmode __wch) - : __hm_(0), + : __str_(__s.get_allocator()), + __hm_(0),  __mode_(__wch)  {  str(__s);