anonymous struct payloads

compiler/types/types.odin

@@ -306,6 +306,42 @@ union_anonymous :: proc(store: ^Store, fields: []Field, tag: Type) -> Type {
 	})
 }
 
+anonymous_struct_fields_equal :: proc(store: ^Store, item: Node, fields: []Field) -> bool {
+	if item.field_count != u32(len(fields)) {
+		return false
+	}
+	start := int(item.field_start)
+	end := start+int(item.field_count)
+	if start < 0 || end > len(store.fields) {
+		return false
+	}
+	for field, index in fields {
+		existing := store.fields[start+index]
+		if existing.name != field.name || existing.type != field.type {
+			return false
+		}
+	}
+	return true
+}
+
+struct_anonymous :: proc(store: ^Store, fields: []Field) -> Type {
+	for existing, index in store.nodes {
+		if existing.kind == .Struct && existing.name == 0 && existing.declared &&
+		   !existing.c_layout && !existing.opaque &&
+		   anonymous_struct_fields_equal(store, existing, fields) {
+			return DYNAMIC_START+Type(index)
+		}
+	}
+	start := u32(len(store.fields))
+	append(&store.fields, ..fields)
+	return intern(store, Node{
+		kind=.Struct,
+		field_start=start,
+		field_count=u32(len(fields)),
+		declared=true,
+	})
+}
+
 variant_id :: proc(store: ^Store, name: u32, payload: Type) -> (u16, bool) {
 	for variant in store.variants {
 		if variant.name == name && variant.payload == payload {