MAINT-1175: Ditch LLTypeInfoLookup, make map<const type_info*> work.

Instead of forbidding std::map<const std::type_info*, ...> outright (which
includes LLRegistry<const std::type_info*, ...> and LLRegistrySingleton<const
std::type_info*, ...>), try to make it work by specializing std::less<const
std::type_info*> to use std::type_info::before().
Make LLRegistryDefaultComparator<T> use std::less<T> so it can capitalize on
that specialization.

1 files changed, 30 insertions, 0 deletions

diff --git a/indra/llcommon/llstl.h b/indra/llcommon/llstl.h
index 8ad12c9a03..6109b21546 100644
--- a/indra/llcommon/llstl.h
+++ b/indra/llcommon/llstl.h
@@ -33,6 +33,7 @@
 #include <vector>
 #include <set>
 #include <deque>
+#include <typeinfo>
 
 // Use to compare the first element only of a pair
 // e.g. typedef std::set<std::pair<int, Data*>, compare_pair<int, Data*> > some_pair_set_t; 
@@ -470,4 +471,33 @@ llbind2nd(const _Operation& __oper, const _Tp& __x)
   return llbinder2nd<_Operation>(__oper, _Arg2_type(__x));
 }
 
+/**
+ * Specialize std::less<std::type_info*> to use std::type_info::before().
+ * See MAINT-1175. It is NEVER a good idea to directly compare std::type_info*
+ * because, on Linux, you might get different std::type_info* pointers for the
+ * same type (from different load modules)!
+ */
+namespace std
+{
+    template <>
+    struct less<const std::type_info*>:
+        public std::binary_function<const std::type_info*, const std::type_info*, bool>
+    {
+        bool operator()(const std::type_info* lhs, const std::type_info* rhs) const
+        {
+            return lhs->before(*rhs);
+        }
+    };
+
+    template <>
+    struct less<std::type_info*>:
+        public std::binary_function<std::type_info*, std::type_info*, bool>
+    {
+        bool operator()(std::type_info* lhs, std::type_info* rhs) const
+        {
+            return lhs->before(*rhs);
+        }
+    };
+} // std
+
 #endif // LL_LLSTL_H