1 files changed, 27 insertions, 0 deletions
diff --git a/abi/iface.go b/abi/iface.go
new file mode 100644
index 0000000..676a27d
--- /dev/null
+++ b/abi/iface.go
@@ -0,0 +1,27 @@
+// Copyright 2023 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package abi
+
+import "unsafe"
+
+// The first word of every non-empty interface type contains an *ITab.
+// It records the underlying concrete type (Type), the interface type it
+// is implementing (Inter), and some ancillary information.
+//
+// allocated in non-garbage-collected memory
+type ITab struct {
+	Inter *InterfaceType
+	Type  *Type
+	Hash  uint32     // copy of Type.Hash. Used for type switches.
+	Fun   [1]uintptr // variable sized. fun[0]==0 means Type does not implement Inter.
+}
+
+// EmptyInterface describes the layout of a "interface{}" or a "any."
+// These are represented differently than non-empty interface, as the first
+// word always points to an abi.Type.
+type EmptyInterface struct {
+	Type *Type
+	Data unsafe.Pointer
+}