From ce7710e9c39dc6cd636ee965f0c336a805442adf Mon Sep 17 00:00:00 2001
From: greg7mdp <greg7mdp@gmail.com>
Date: Tue, 21 Jun 2022 21:03:16 -0400
Subject: [PATCH] Fix HashtableDebugAccess as in gtl

---
 parallel_hashmap/phmap.h | 23 ++++++++++++++++++-----
 1 file changed, 18 insertions(+), 5 deletions(-)

diff --git a/parallel_hashmap/phmap.h b/parallel_hashmap/phmap.h
index 3788d1f..8f79cd6 100644
--- a/parallel_hashmap/phmap.h
+++ b/parallel_hashmap/phmap.h
@@ -621,7 +621,7 @@ const typename T::key_type& GetKey(const typename T::key_type& key, char) {
 // container.
 // --------------------------------------------------------------------------
 template <class Container, typename Enabler = void>
-struct HashtableDebugAccess 
+struct HashtableDebugAccess
 {
     // Returns the number of probes required to find `key` in `c`.  The "number of
     // probes" is a concept that can vary by container.  Implementations should
@@ -4394,8 +4394,16 @@ namespace hashtable_debug_internal {
 
 // --------------------------------------------------------------------------
 // --------------------------------------------------------------------------
+
+template<typename, typename = void >
+struct has_member_type_raw_hash_set : std::false_type
+{};
+template<typename T>
+struct has_member_type_raw_hash_set<T, phmap::void_t<typename T::raw_hash_set>> : std::true_type
+{};
+
 template <typename Set>
-struct HashtableDebugAccess<Set, phmap::void_t<typename Set::raw_hash_set>> 
+struct HashtableDebugAccess<Set, typename std::enable_if<has_member_type_raw_hash_set<Set>::value>::type>
 {
     using Traits = typename Set::PolicyTraits;
     using Slot = typename Traits::slot_type;
@@ -4454,9 +4462,15 @@ struct HashtableDebugAccess<Set, phmap::void_t<typename Set::raw_hash_set>>
 };
 
 
-#if !defined(__clang__) // compilation error with clang++-12 -stdc++=20 (should fix )
+template<typename, typename = void >
+struct has_member_type_EmbeddedSet : std::false_type
+{};
+template<typename T>
+struct has_member_type_EmbeddedSet<T, phmap::void_t<typename T::EmbeddedSet>> : std::true_type
+{};
+
 template <typename Set>
-struct HashtableDebugAccess<Set, phmap::void_t<typename Set::EmbeddedSet>> {
+struct HashtableDebugAccess<Set, typename std::enable_if<has_member_type_EmbeddedSet<Set>::value>::type> {
     using Traits = typename Set::PolicyTraits;
     using Slot = typename Traits::slot_type;
     using EmbeddedSet = typename Set::EmbeddedSet;
@@ -4468,7 +4482,6 @@ struct HashtableDebugAccess<Set, phmap::void_t<typename Set::EmbeddedSet>> {
         return HashtableDebugAccess<EmbeddedSet>::GetNumProbes(inner_set, key);
     }
 };
-#endif
 
 }  // namespace hashtable_debug_internal
 }  // namespace priv