object: string: add front, back, and pop_back functions

object/include/blue/object/string.h

@@ -51,6 +51,11 @@ BLUE_API void b_string_clear(b_string *str);
 BLUE_API size_t b_string_get_size(const b_string *str, b_strlen_flags flags);
 BLUE_API size_t b_string_get_capacity(const b_string *str);
 
+BLUE_API char b_string_front(const b_string *str);
+BLUE_API char b_string_back(const b_string *str);
+
+BLUE_API void b_string_pop_back(b_string *str);
+
 BLUE_API const char *b_string_ptr(const b_string *str);
 
 BLUE_API char *b_strdup(const char *s);

object/include/blue/object/type.h

@@ -26,6 +26,7 @@ typedef enum b_fundamental_type_id {
 	B_OBJECT_TYPE_STRING,
 	B_OBJECT_TYPE_TREE,
 	B_OBJECT_TYPE_UUID,
+	B_OBJECT_TYPE_PATH,
 	B_OBJECT_TYPE_FILE,
 	B_OBJECT_TYPE_DIRECTORY,
 } b_fundamental_type_id;