Fix for problem with OrderedHashSet causing crash (#3251)

* Fix for problem with OrderedHashSet causing crashes during running tests on on g++ 7.3

* Fix typo

2 files changed, 32 insertions, 4 deletions

diff --git a/premake5.lua b/premake5.lua
index 3e4ac1100..98bb2b6a0 100644
--- a/premake5.lua
+++ b/premake5.lua
@@ -403,6 +403,9 @@ workspace "slang"
         }
     filter { "toolset:gcc*", "language:C++" }
         buildoptions { "-Wno-class-memaccess" }
+        -- If a function returns an address/reference to a local, we want it to produce an error, because 
+        -- it probably means something very bad.
+        buildoptions { "-Werror=return-local-addr" }
     filter { "toolset:clang", "language:C++" }
         buildoptions { "-Wno-assume" }
     filter { "toolset:clang or gcc*", "language:C++" }
diff --git a/source/core/slang-dictionary.h b/source/core/slang-dictionary.h
index ff7e201bf..ba4672740 100644
--- a/source/core/slang-dictionary.h
+++ b/source/core/slang-dictionary.h
@@ -75,6 +75,32 @@ namespace Slang
         return KeyValuePair<TKey, TValue>(k, v);
     }
 
+    namespace KeyValueDetail {
+
+    template <typename KEY, typename VALUE>
+    SLANG_FORCE_INLINE const KEY* getKey(const std::pair<KEY, VALUE>* in)
+    {
+        return &in->first;
+    }
+    template <typename KEY, typename VALUE>
+    SLANG_FORCE_INLINE const KEY* getKey(const KeyValuePair<KEY, VALUE>* in)
+    {
+        return &in->key;
+    }
+
+    template <typename KEY, typename VALUE>
+    SLANG_FORCE_INLINE const VALUE* getValue(const std::pair<KEY, VALUE>* in)
+    {
+        return &in->second;
+    }
+    template <typename KEY, typename VALUE>
+    SLANG_FORCE_INLINE const VALUE* getValue(const KeyValuePair<KEY, VALUE>* in)
+    {
+        return &in->value;
+    }
+
+    } // namespace KeyValueDetail
+
     const float kMaxLoadFactor = 0.7f;
 
     template<typename TKey, typename TValue, typename Hash = Slang::Hash<TKey>, typename KeyEqual = std::equal_to<TKey>>
@@ -321,14 +347,13 @@ namespace Slang
             Iterator() = default;
             const T& operator*() const
             {
-                const auto& [k, v] = *iter;
-                return k;
+                return *KeyValueDetail::getKey(std::addressof(*iter));
             }
             const T* operator->() const
             {
-                const auto& [k, v] = *iter;
-                return &k;
+                return KeyValueDetail::getKey(std::addressof(*iter));
             }
+
             Iterator& operator++()
             {
                 ++iter;