candidate workaround for visual studio loss of cv qualifier bug

Author: danpoe

src/util/sharing_map.h

@@ -673,7 +673,7 @@ SHARING_MAPT2(, size_type)::erase_all(
 ///   (possible values `false` or `unknown`)
 /// \return Pair of const reference to existing or newly inserted element, and
 ///   boolean indicating if new element was inserted
-SHARING_MAPT2(, const_find_type)::insert(
+SHARING_MAPT2(const, const_find_type)::insert(
   const key_type &k,
   const mapped_type &m,
   const tvt &key_exists)
@@ -697,7 +697,7 @@ SHARING_MAPT2(, const_find_type)::insert(
 }
 
 // Insert element, return const reference
-SHARING_MAPT2(, const_find_type)::insert(
+SHARING_MAPT2(const, const_find_type)::insert(
   const value_type &p,
   const tvt &key_exists)
 {