Replace a CRIT_ERR in combine by trying,throwing and catching

PS: I want to replace all similar CRIT_ERR's like this, opinions ?

src/combine.cc

@@ -40,7 +40,7 @@ struct combine_data {
 	char *right;
 };
 
-void parse_combine_arg(struct text_object *obj, const char *arg, void *free_at_crash)
+void parse_combine_arg(struct text_object *obj, const char *arg)
 {
 	struct combine_data *cd;
 	unsigned int i,j;
@@ -89,7 +89,7 @@ void parse_combine_arg(struct text_object *obj, const char *arg, void *free_at_c
 		extract_variable_text_internal(obj->sub->sub, cd->right);
 		obj->data.opaque = cd;
 	} else {
-		CRIT_ERR(obj, free_at_crash, "combine needs arguments: <text1> <text2>");
+		throw combine_needs_2_args_error();
 	}
 }
 

src/combine.h

@@ -30,7 +30,7 @@
 #ifndef _COMBINE_H
 #define _COMBINE_H
 
-void parse_combine_arg(struct text_object *, const char *, void *);
+void parse_combine_arg(struct text_object *, const char *);
 void print_combine(struct text_object *, char *, int);
 void free_combine(struct text_object *);
 

src/conky.cc

@@ -4495,6 +4495,11 @@ int main(int argc, char **argv)
 	}
 	catch(fork_throw &e) { return EXIT_SUCCESS; }
 	catch(unknown_arg_throw &e) { return EXIT_FAILURE; }
+	catch(obj_create_error &e) {
+		std::cerr << e.what() << std::endl;
+		clean_up(NULL, NULL);
+		return EXIT_FAILURE;
+	}
 
 #ifdef BUILD_CURL
 	curl_global_cleanup();

src/core.cc

@@ -1726,8 +1726,14 @@ struct text_object *construct_text_object(char *s, const char *arg, long
 		parse_scroll_arg(obj, arg, free_at_crash, s);
 		obj->callbacks.print = &print_scroll;
 		obj->callbacks.free = &free_scroll;
-	END OBJ_ARG(combine, 0, "combine needs arguments: <text1> <text2>")
+	END OBJ(combine, 0)
-		parse_combine_arg(obj, arg, free_at_crash);
+		try {
+			parse_combine_arg(obj, arg);
+		}
+		catch(combine_needs_2_args_error &e) {
+			free(obj);
+			throw obj_create_error(e.what());
+		}
 		obj->callbacks.print = &print_combine;
 		obj->callbacks.free = &free_combine;
 #ifdef BUILD_NVIDIA
@@ -1955,8 +1961,15 @@ int extract_variable_text_internal(struct text_object *retval, const char *const
 					tmp_p++;
 				}
 
-				obj = construct_text_object(buf, arg,
+				try {
+					obj = construct_text_object(buf, arg,
 						line, &ifblock_opaque, orig_p);
+				}
+				catch(obj_create_error &e) {
+					free(buf);
+					free(orig_p);
+					throw e;
+				}
 				if (obj != NULL) {
 					append_object(retval, obj);
 				}

src/logging.h

@@ -47,6 +47,18 @@ public:
 	unknown_arg_throw(const std::string &msg) : std::runtime_error(msg) {}
 };
 
+class combine_needs_2_args_error : public std::runtime_error {
+public:
+	combine_needs_2_args_error() : std::runtime_error("combine needs arguments: <text1> <text2>") {}
+	combine_needs_2_args_error(const std::string &msg) : std::runtime_error(msg) {}
+};
+
+class obj_create_error : public std::runtime_error {
+public:
+	obj_create_error() : std::runtime_error("Failed to create object") {}
+	obj_create_error(const std::string &msg) : std::runtime_error(msg) {}
+};
+
 void clean_up(void *memtofree1, void* memtofree2);
 void clean_up_without_threads(void *memtofree1, void* memtofree2);