Sema: implement union value equality at comptime

Still TODO is extern unions.
2022-02-26 18:01:12 -07:00
parent e999a925fa
commit 32e89a98d8
3 changed files with 27 additions and 2 deletions
--- a/src/type.zig
+++ b/src/type.zig
@@ -2934,6 +2934,14 @@ pub const Type = extern union {
        };
    }

+    /// Asserts the type is a union; returns the tag type, even if the tag will
+    /// not be stored at runtime.
+    pub fn unionTagTypeHypothetical(ty: Type) Type {
+        const union_obj = ty.cast(Payload.Union).?.data;
+        assert(union_obj.haveFieldTypes());
+        return union_obj.tag_ty;
+    }
+
    pub fn unionFields(ty: Type) Module.Union.Fields {
        const union_obj = ty.cast(Payload.Union).?.data;
        assert(union_obj.haveFieldTypes());