[gcc r15-8723] libstdc++: Ensure that std::vector allocator has bool value_type

[Jonathan Wakely via Gcc-cvs]

https://gcc.gnu.org/g:75df481fcc381d6aaefdbe2ef1d66927e30b5743

commit r15-8723-g75df481fcc381d6aaefdbe2ef1d66927e30b5743
Author: Jonathan Wakely <jwak...@redhat.com>
Date:   Fri Mar 21 22:49:44 2025 +0000

    libstdc++: Ensure that std::vector<bool> allocator has bool value_type
    
    This is the subject of LWG 4228 which notes that libstdc++ doesn't
    enforce this requirement. That's just a bug because I forgot to add it
    to vector<bool> when adding it elsewhere.
    
    For consistency with the other containers we should not allow incorrect
    allocator types for strict -std=c++NN modes, but it is very late to make
    that change for GCC 15 so this only enables the assertion for C++20
    (where it's required). For GCC 16 we can enable it for strict modes too.
    
    libstdc++-v3/ChangeLog:
    
            * include/bits/stl_bvector.h (vector<bool, A>): Enforce the
            C++20 requirement that the allocator's value_type matches the
            container.
            * testsuite/23_containers/vector/bool/cons/from_range.cc: Fix
            incorrect allocator type.
    
    Reviewed-by: Tomasz Kamiński <tkami...@redhat.com>

Diff:
---
 libstdc++-v3/include/bits/stl_bvector.h                             | 4 ++++
 libstdc++-v3/testsuite/23_containers/vector/bool/cons/from_range.cc | 2 +-
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/libstdc++-v3/include/bits/stl_bvector.h 
b/libstdc++-v3/include/bits/stl_bvector.h
index 2292eec54ad7..3ee15eaa938c 100644
--- a/libstdc++-v3/include/bits/stl_bvector.h
+++ b/libstdc++-v3/include/bits/stl_bvector.h
@@ -751,6 +751,10 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
 
 #if __cplusplus >= 201103L
       friend struct std::hash<vector>;
+# if __cplusplus > 201703L // || defined __STRICT_ANSI__
+      static_assert(is_same<typename _Alloc::value_type, bool>::value,
+         "std::vector must have the same value_type as its allocator");
+# endif
 #endif
 
     public:
diff --git 
a/libstdc++-v3/testsuite/23_containers/vector/bool/cons/from_range.cc 
b/libstdc++-v3/testsuite/23_containers/vector/bool/cons/from_range.cc
index f531e7f50396..37f0ecf32ad7 100644
--- a/libstdc++-v3/testsuite/23_containers/vector/bool/cons/from_range.cc
+++ b/libstdc++-v3/testsuite/23_containers/vector/bool/cons/from_range.cc
@@ -71,7 +71,7 @@ test_ranges()
     bool val;
   };
   using rvalue_input_range = test_range<C, input_iterator_wrapper_rval>;
-  do_test<rvalue_input_range>(std::allocator<int>());
+  do_test<rvalue_input_range>(std::allocator<bool>());
 
   return true;
 }