[Bug libstdc++/103191] New: vector<bool> doesn't have any checks enabled by _GLIBCXX_ASSERTIONS

["redi at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103191

            Bug ID: 103191
           Summary: vector<bool> doesn't have any checks enabled by
                    _GLIBCXX_ASSERTIONS
           Product: gcc
           Version: 12.0
            Status: UNCONFIRMED
          Severity: enhancement
          Priority: P3
         Component: libstdc++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: redi at gcc dot gnu.org
  Target Milestone: ---

We should consider this change:

diff --git a/libstdc++-v3/include/bits/stl_bvector.h
b/libstdc++-v3/include/bits/stl_bvector.h
index 1425877a5ea..32e22f5a056 100644
--- a/libstdc++-v3/include/bits/stl_bvector.h
+++ b/libstdc++-v3/include/bits/stl_bvector.h
@@ -1057,12 +1057,18 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
       _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
       reference
       operator[](size_type __n)
-      { return begin()[__n]; }
+      {
+       __glibcxx_requires_subscript(__n);
+       return begin()[__n];
+      }

       _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
       const_reference
       operator[](size_type __n) const
-      { return begin()[__n]; }
+      {
+       __glibcxx_requires_subscript(__n);
+       return begin()[__n];
+      }

     protected:
       _GLIBCXX20_CONSTEXPR
@@ -1106,22 +1112,34 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
       _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
       reference
       front()
-      { return *begin(); }
+      {
+       __glibcxx_requires_nonempty();
+       return *begin();
+      }

       _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
       const_reference
       front() const
-      { return *begin(); }
+      {
+       __glibcxx_requires_nonempty();
+       return *begin();
+      }

       _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
       reference
       back()
-      { return *(end() - 1); }
+      {
+       __glibcxx_requires_nonempty();
+       return *(end() - 1);
+      }

       _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
       const_reference
       back() const
-      { return *(end() - 1); }
+      {
+       __glibcxx_requires_nonempty();
+       return *(end() - 1);
+      }

       // _GLIBCXX_RESOLVE_LIB_DEFECTS
       // DR 464. Suggestion for new member functions in standard containers.