Not sure why I started to experience this now with a recent
GCC/libstdc++ trunk build:
$ cat test.cc
#include <regex>
$ gcc/trunk/inst/bin/g++ -D_GLIBCXX_DEBUG -fsyntax-only test.cc
In file included from
/home/sbergman/gcc/trunk/inst/include/c++/12.0.0/bits/regex_automaton.h:401,
from /home/sbergman/gcc/trunk/inst/include/c++/12.0.0/regex:60,
from test.cc:1:
/home/sbergman/gcc/trunk/inst/include/c++/12.0.0/bits/regex_automaton.tcc: In member
function ‘std::__detail::_StateSeq<_TraitsT>
std::__detail::_StateSeq<_TraitsT>::_M_clone()’:
/home/sbergman/gcc/trunk/inst/include/c++/12.0.0/bits/regex_automaton.tcc:197:12:
error: ‘map’ is not a member of ‘std’
197 | std::map<_StateIdT, _StateIdT> __m;
| ^~~
[...]
In file included from /home/sbergman/gcc/trunk/inst/include/c++/12.0.0/regex:62,
from test.cc:1:
/home/sbergman/gcc/trunk/inst/include/c++/12.0.0/bits/regex_compiler.h: At
global scope:
/home/sbergman/gcc/trunk/inst/include/c++/12.0.0/bits/regex_compiler.h:541:12:
error: ‘vector’ in namespace ‘std’ does not name a template type
541 | std::vector<_CharT> _M_char_set;
| ^~~~~~
[...]
where neither the use of std::map in bits/regex_automaton.tcc nor the
use of std::vector in bits/regex_compiler.h are in _GLIBCXX_DEBUG-only
code (but compiling without -D_GLIBCXX_DEBUG succeeded).
Anyway, what would apparently fix it for me is
diff --git a/libstdc++-v3/include/std/regex b/libstdc++-v3/include/std/regex
index 04fb8b2d971..29fd2956fd0 100644
--- a/libstdc++-v3/include/std/regex
+++ b/libstdc++-v3/include/std/regex
@@ -42,6 +42,11 @@
#include <stdexcept>
#include <string>
+#if defined _GLIBCXX_DEBUG
+#include <map>
+#include <vector>
+#endif
+
#include <ext/aligned_buffer.h>
#include <ext/numeric_traits.h>
#include <bits/shared_ptr.h>
