Cannot use void as a generic parameter #1546. Interfaces now support .ptr and .type directly without casting to any.

releasenotes.md

@@ -11,6 +11,7 @@
 - Deprecate `@adhoc`, allow non-nested ad hoc generic types.
 - Constant bytes <=> char[] conversion should work #1514.
 - Infer now works across ternary.
+- Interfaces now support .ptr and .type directly without casting to `any`.
 
 ### Fixes
 - `Unsupported int[*] $x = { 1, 2, 3, 4 }` #1489.
@@ -27,6 +28,7 @@
 - Crash returning struct or vector from function using ternary expression #1537.
 - Improved error message on invalid subscript index type #1535.
 - Improved error message when declaring a variable `void!`.
+- Cannot use void as a generic parameter #1546
 
 ### Stdlib changes
 - Remove unintended print of `char[]` as String

src/compiler/compiler_internal.h

@@ -2584,6 +2584,17 @@ INLINE bool type_is_wildcard(Type *type)
 	return type == type_wildcard || type == type_wildcard_optional;
 }
 
+INLINE bool type_is_fault_raw(Type *type)
+{
+	switch (type->type_kind)
+	{
+		case TYPE_FAULTTYPE:
+		case TYPE_ANYFAULT:
+			return true;
+		default:
+			return false;
+	}
+}
 INLINE bool type_is_any_raw(Type *type)
 {
 	switch (type->type_kind)

src/compiler/sema_decls.c

@@ -4080,9 +4080,8 @@ static bool sema_generate_parameterized_name_to_scratch(SemaContext *context, Mo
 			switch (type_storage_type(type))
 			{
 				case STORAGE_NORMAL:
-					break;
 				case STORAGE_VOID:
-					RETURN_SEMA_ERROR(type_info, "A 'void' type cannot be used as a parameter type.");
+					break;
 				case STORAGE_WILDCARD:
 					RETURN_SEMA_ERROR(type_info, "The type is undefined and cannot be used as a parameter type.");
 				case STORAGE_COMPILE_TIME:

src/compiler/sema_expr.c

@@ -4749,7 +4749,7 @@ static inline bool sema_expr_analyse_access(SemaContext *context, Expr *expr, bo
 	const char *kw = identifier->identifier_expr.ident;
 	if (kw_type == kw)
 	{
-		if (flat_type->type_kind == TYPE_ANY)
+		if (type_is_any_raw(flat_type))
 		{
 			expr_rewrite_to_builtin_access(expr, parent, ACCESS_TYPEOFANY, type_typeid);
 			return true;
@@ -4816,7 +4816,7 @@ CHECK_DEEPER:
 			expr_rewrite_to_builtin_access(expr, current_parent, ACCESS_PTR, type_get_ptr(flat_type->array.base));
 			return true;
 		}
-		if (flat_type->type_kind == TYPE_ANY)
+		if (type_is_any_raw(flat_type))
 		{
 			expr_rewrite_to_builtin_access(expr, current_parent, ACCESS_PTR, type_voidptr);
 			return true;
@@ -4864,7 +4864,7 @@ CHECK_DEEPER:
 				return true;
 			}
 		}
-		if (flat_type->type_kind == TYPE_FAULTTYPE || flat_type->type_kind == TYPE_ANYFAULT)
+		if (type_is_fault_raw(flat_type))
 		{
 			if (sema_cast_const(current_parent))
 			{
@@ -7461,7 +7461,7 @@ static inline bool sema_expr_analyse_optional(SemaContext *context, Expr *expr,
 
 	Type *type = inner->type->canonical;
 
-	if (type->type_kind != TYPE_FAULTTYPE && type->type_kind != TYPE_ANYFAULT)
+	if (!type_is_fault_raw(type))
 	{
 		if (failed_ref) goto ON_FAILED;
 		RETURN_SEMA_ERROR(inner, "You cannot use the '?' operator on expressions of type %s",
@@ -7726,6 +7726,7 @@ static inline bool sema_expr_analyse_decl_element(SemaContext *context, Designat
 				*member_ref = NULL;
 				*return_type = actual_type->array.base;
 				return true;
+			case TYPE_INTERFACE:
 			case TYPE_ANY:
 				*member_ref = NULL;
 				*return_type = type_voidptr;
@@ -9160,7 +9161,7 @@ bool sema_analyse_expr_rhs(SemaContext *context, Type *to, Expr *expr, bool allo
 	if (to && allow_optional && to_canonical != rhs_type_canonical && rhs_type_canonical->type_kind == TYPE_FAULTTYPE)
 	{
 		Type *flat = type_flatten(to);
-		if (flat != type_anyfault && flat->type_kind != TYPE_FAULTTYPE && sema_cast_const(expr))
+		if (!type_is_fault_raw(flat) && sema_cast_const(expr))
 		{
 			if (no_match_ref) goto NO_MATCH_REF;
 			print_error_after(expr->span, "You need to add a trailing '?' here to make this an optional.");

test/test_suite/any/interface_ptr.c3

@@ -0,0 +1,8 @@
+interface Abc {}
+
+fn void main()
+{
+	Abc y;
+	typeid z = y.type;
+	void* x = y.ptr;
+}

test/test_suite/generic/generic_void.c3t

@@ -0,0 +1,29 @@
+// #target: macos-x64
+module test(<Type>);
+
+def Callback = fn Type();
+
+module mymain;
+
+import std::io;
+import test;
+
+def VoidCb = test::Callback(<void>);
+
+fn int main()
+{
+	VoidCb a = null;
+	void *b = a;
+	return 0;
+}
+/* #expect: mymain.ll
+
+define i32 @main() #0 {
+entry:
+  %a = alloca ptr, align 8
+  %b = alloca ptr, align 8
+  store ptr null, ptr %a, align 8
+  %0 = load ptr, ptr %a, align 8
+  store ptr %0, ptr %b, align 8
+  ret i32 0
+}