Improve diagnostics when an invalid hash is used in an unordered container.
This patch adds a static assertion that the specified hash meets
the requirements of an enabled hash, and it ensures that the static
assertion is evaluated before __compressed_pair is instantiated.
That way the static assertion diagnostic is emitted first.
llvm-svn: 296565
diff --git a/libcxx/include/__hash_table b/libcxx/include/__hash_table
index 6d6a6a1..9d9a290 100644
--- a/libcxx/include/__hash_table
+++ b/libcxx/include/__hash_table
@@ -871,11 +871,20 @@
template <class _Key, class _Hash, class _Equal, class _Alloc>
struct __diagnose_hash_table_helper {
static constexpr bool __trigger_diagnostics()
- _LIBCPP_DIAGNOSE_WARNING(!__invokable<_Hash const&, _Key const&>::value,
- "the specified hash functor does not provide a const call operator")
- _LIBCPP_DIAGNOSE_WARNING(!__invokable<_Equal const&, _Key const&, _Key const&>::value,
- "the specified comparator type does not provide a const call operator")
- { return true; }
+ _LIBCPP_DIAGNOSE_WARNING(__has_enabled_hash<_Key, _Hash>::value
+ && !__invokable<_Hash const&, _Key const&>::value,
+ "the specified hash functor does not provide a const call operator")
+ _LIBCPP_DIAGNOSE_WARNING(is_copy_constructible<_Equal>::value
+ && !__invokable<_Equal const&, _Key const&, _Key const&>::value,
+ "the specified comparator type does not provide a const call operator")
+ {
+ static_assert(__has_enabled_hash<_Key, _Hash>::value,
+ "the specified hash functor does not meet the requirements for an "
+ "enabled hash");
+ static_assert(is_copy_constructible<_Equal>::value,
+ "the specified comparator is required to be copy constructible");
+ return true;
+ }
};
template <class _Key, class _Value, class _Hash, class _Equal, class _Alloc>
@@ -951,6 +960,10 @@
typedef allocator_traits<__pointer_allocator> __pointer_alloc_traits;
typedef typename __bucket_list_deleter::pointer __node_pointer_pointer;
+#ifndef _LIBCPP_CXX03_LANG
+ static_assert(__diagnose_hash_table_helper<_Tp, _Hash, _Equal, _Alloc>::__trigger_diagnostics(), "");
+#endif
+
// --- Member data begin ---
__bucket_list __bucket_list_;
__compressed_pair<__first_node, __node_allocator> __p1_;
@@ -1482,13 +1495,13 @@
template <class _Tp, class _Hash, class _Equal, class _Alloc>
__hash_table<_Tp, _Hash, _Equal, _Alloc>::~__hash_table()
{
+#if defined(_LIBCPP_CXX03_LANG)
static_assert((is_copy_constructible<key_equal>::value),
"Predicate must be copy-constructible.");
static_assert((is_copy_constructible<hasher>::value),
"Hasher must be copy-constructible.");
-#ifndef _LIBCPP_CXX03_LANG
- static_assert(__diagnose_hash_table_helper<_Tp, _Hash, _Equal, _Alloc>::__trigger_diagnostics(), "");
#endif
+
__deallocate_node(__p1_.first().__next_);
#if _LIBCPP_DEBUG_LEVEL >= 2
__get_db()->__erase_c(this);