// behavior for structs, which allow read but not write
	// of unexported fields.

	var e unsafe.Pointer
	if (tt.Key == stringType || key.kind() == String) && tt.Key == key.typ() && tt.Elem.Size() <= abi.MapMaxElemBytes {
		k := *(*string)(key.ptr)
		e = mapaccess_faststr(v.typ(), v.pointer(), k)
	} else {
		key = key.assignTo("reflect.Value.MapIndex", tt.Key, nil)
		var k unsafe.Pointer
		if key.flag&flagIndir != 0 {