fix regression(?)

x/Cargo.toml

@@ -4,7 +4,7 @@ version = "0.1.0"
 edition = "2021"
 
 [features]
-default = ["core"]
+default = ["core", "xpat"]
 core = ["sub_core"]
 macros = ["sub_macros"]
 libm = ["sub_libm"]