+
+unknown_keyword::unknown_keyword(const string &k):
+ runtime_error(k)
+{ }
+
+
+invalid_signature::invalid_signature(const string &k, const string &s):
+ runtime_error(format("%s %s", k, s))
+{ }
+
+
+no_collection::no_collection(const type_info &t):
+ runtime_error(Debug::demangle(t.name()))
+{ }
+