diff --git a/lib/std/builtin.c3 b/lib/std/builtin.c3
index 0db824319..07ca25698 100644
--- a/lib/std/builtin.c3
+++ b/lib/std/builtin.c3
@@ -3,16 +3,34 @@
 // a copy of which can be found in the LICENSE_STDLIB file.
 module std::builtin;
 
-macro scope(&variable; @body) @autoimport
+optenum VarCastResult
+{
+	TYPE_MISMATCH
+}
+
+/**
+ * Stores a variable on the stack, then restores it at the end of the
+ * macro scope.
+ *
+ * @param variable `the variable to store and restore`
+ **/
+macro void scope(&variable; @body) @autoimport
 {
 	$typeof(variable) temp = variable;
 	defer variable = temp;
 	@body();
 }
 
+/**
+ * Convert a variant type to a type, returning an failure if there is a type mismatch.
+ *
+ * @param v `the variant to convert to the given type.`
+ * @param $Type `the type to convert to`
+ * @return `The variant.ptr converted to its type.`
+ **/
 macro varcast(variant v, $Type) @autoimport
 {
-	if (v.type != $Type.typeid) return null;
+	if (v.type != $Type.typeid) return VarCastResult.TYPE_MISMATCH!;
 	return ($Type*)v.ptr;
 }
 
diff --git a/src/compiler/compiler_internal.h b/src/compiler/compiler_internal.h
index 219cb6463..50ab6a671 100644
--- a/src/compiler/compiler_internal.h
+++ b/src/compiler/compiler_internal.h
@@ -1578,13 +1578,6 @@ extern Type *type_cuint;
 extern const char *attribute_list[NUMBER_OF_ATTRIBUTES];
 extern const char *builtin_list[NUMBER_OF_BUILTINS];
 
-extern const char *kw_at_return;
-extern const char *kw_at_checked;
-extern const char *kw_at_ensure;
-extern const char *kw_at_optreturn;
-extern const char *kw_at_param;
-extern const char *kw_at_require;
-
 extern const char *kw_std;
 extern const char *kw_max;
 extern const char *kw_min;
@@ -1608,8 +1601,6 @@ extern const char *kw_nan;
 extern const char *kw_noinline;
 extern const char *kw_main;
 extern const char *kw_ordinal;
-extern const char *kw_reqparse;
-extern const char *kw_require;
 extern const char *kw_pure;
 extern const char *kw_param;
 extern const char *kw_ptr;
diff --git a/src/compiler/symtab.c b/src/compiler/symtab.c
index 159be6b56..2be8ba335 100644
--- a/src/compiler/symtab.c
+++ b/src/compiler/symtab.c
@@ -39,13 +39,6 @@ static SymTab symtab;
 const char *attribute_list[NUMBER_OF_ATTRIBUTES];
 const char *builtin_list[NUMBER_OF_BUILTINS];
 
-const char *kw_at_return;
-const char *kw_at_checked;
-const char *kw_at_ensure;
-const char *kw_at_optreturn;
-const char *kw_at_param;
-const char *kw_at_require;
-
 const char *kw_in;
 const char *kw_out;
 const char *kw_inout;
@@ -72,8 +65,6 @@ const char *kw_ordinal;
 const char *kw_param;
 const char *kw_ptr;
 const char *kw_pure;
-const char *kw_reqparse;
-const char *kw_require;
 const char *kw_std;
 const char *kw_sizeof;
 const char *kw_values;
@@ -159,7 +150,7 @@ void symtab_init(uint32_t capacity)
 	kw_param = KW_DEF("param");
 	kw_ptr = KW_DEF("ptr");
 	kw_pure = KW_DEF("pure");
-	kw_require = KW_DEF("require");
+	KW_DEF("require");
 	kw_std = KW_DEF("std");
 	kw_values = KW_DEF("values");
 	kw_incr = KW_DEF("incr");