1// Copyright 2018 The Go Authors. All rights reserved. 2// Use of this source code is governed by a BSD-style 3// license that can be found in the LICENSE file. 4 5// Package pragma provides types that can be embedded into a struct to 6// statically enforce or prevent certain language properties. 7package pragma 8 9import "sync" 10 11// NoUnkeyedLiterals can be embedded in a struct to prevent unkeyed literals. 12type NoUnkeyedLiterals struct{} 13 14// DoNotImplement can be embedded in an interface to prevent trivial 15// implementations of the interface. 16// 17// This is useful to prevent unauthorized implementations of an interface 18// so that it can be extended in the future for any protobuf language changes. 19type DoNotImplement interface{ ProtoInternal(DoNotImplement) } 20 21// DoNotCompare can be embedded in a struct to prevent comparability. 22type DoNotCompare [0]func() 23 24// DoNotCopy can be embedded in a struct to help prevent shallow copies. 25// This does not rely on a Go language feature, but rather a special case 26// within the vet checker. 27// 28// See https://golang.org/issues/8005. 29type DoNotCopy [0]sync.Mutex 30