X-Git-Url: https://git.lyx.org/gitweb/?a=blobdiff_plain;f=src%2Fsupport%2FCache.h;h=f1738c7147a0bc669d1fafb61c58224ffbe24726;hb=3561caa3a171a5984ee7a10b7ea82f7f4b7226e8;hp=75427809b40e2442d1bc622124d6a4dc327196d6;hpb=33b696c8acf2e64b44d449180781de6dbc203709;p=lyx.git

diff --git a/src/support/Cache.h b/src/support/Cache.h
index 75427809b4..f1738c7147 100644
--- a/src/support/Cache.h
+++ b/src/support/Cache.h
@@ -33,11 +33,15 @@ namespace lyx {
  */
 template <class Key, class Val>
 class Cache : private QCache<Key, Val> {
+#if !(defined(__GNUC__) && (__GNUC__ == 4) && (__GNUC_MINOR__ == 6))
 	static_assert(std::is_copy_constructible<Val>::value,
 	              "lyx::Cache only stores copyable objects!");
 	static_assert(std::is_default_constructible<Val>::value,
 	              "lyx::Cache only stores default-constructible objects!");
 	using Q = QCache<Key, Val>;
+#else
+	typedef QCache<Key, Val> Q;
+#endif
 
 public:
 	///
@@ -47,15 +51,17 @@ public:
 	{
 		return Q::insert(key, new Val(std::move(object)), cost);
 	}
-	// Returns the default value (e.g. null pointer) before using the result. If
-	// this is not convenient for your type, check if it exists beforehand with
-	// Cache::contains.
+	// Returns the default value (e.g. null pointer) if not found in the
+	// cache. If this is not convenient for your class Val, check if it exists
+	// beforehand with Cache::contains.
 	Val object(Key const & key) const
 	{
 		if (Val * obj = Q::object(key))
 			return *obj;
 		return Val();
 	}
+	/// Synonymous for object, same remark as above.
+	Val operator[](Key const & key) const { return object(key); }
 	/// Everything from QCache except QCache::take.
 	using Q::clear;
 	using Q::contains;
@@ -67,7 +73,6 @@ public:
 	int max_cost() const { return Q::maxCost(); }
 	void set_max_cost(int cost) { Q::setMaxCost(cost); }
 	int total_cost() const { return Q::totalCost(); }
-	Val operator[](Key const & key) const { return object(key); }
 };
 
 } // namespace lyx