| // run | |
| // Copyright 2022 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 main | |
| type TaskInput interface { | |
| deps() []*taskDefinition | |
| } | |
| type Value[T any] interface { | |
| metaValue | |
| } | |
| type metaValue interface { | |
| TaskInput | |
| } | |
| type taskDefinition struct { | |
| } | |
| type taskResult struct { | |
| task *taskDefinition | |
| } | |
| func (tr *taskResult) deps() []*taskDefinition { | |
| return nil | |
| } | |
| func use[T any](v Value[T]) { | |
| _, ok := v.(*taskResult) | |
| if !ok { | |
| panic("output must be *taskResult") | |
| } | |
| } | |
| func main() { | |
| tr := &taskResult{&taskDefinition{}} | |
| use[string](Value[string](tr)) | |
| } |