[libcxx-commits] [libcxx] [libc++] Update container adaptors' type verification tests (PR #224810)

[A. Jiang via libcxx-commits]

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@@ -85,8 +85,10 @@ class flat_map {
   template <class, class, class, class, class>
   friend class flat_map;
 
-  static_assert(is_same_v<_Key, typename _KeyContainer::value_type>);
-  static_assert(is_same_v<_Tp, typename _MappedContainer::value_type>);
+  static_assert(is_same_v<_Key, typename _KeyContainer::value_type>,
+                "The stored elements' key type must match the underlying key container's value_type.");
+  static_assert(is_same_v<_Tp, typename _MappedContainer::value_type>,
+                "The stored elements' mapped type must match the underlying mapped container's value_type.");
   static_assert(!is_same_v<_KeyContainer, std::vector<bool>>, "vector<bool> is not a sequence container");
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frederick-vs-ja wrote:

I'd like leave do this to the next PR. Maybe it's clearer to say "The underlying key container must not be std::vector<bool> which is not a sequence container.".

https://github.com/llvm/llvm-project/pull/224810