"path/filepath"
	"time"
)

const prog = `
package main

import _ "os/signal"

func main() {
  c := make(chan int)
  c <- 1
}
`

func main() {
	dir, err := ioutil.TempDir("", "21576")
	if err != nil {
		log.Fatal(err)
	}
	defer os.RemoveAll(dir)

	file := filepath.Join(dir, "main.go")
	if err := ioutil.WriteFile(file, []byte(prog), 0655); err != nil {
		log.Fatalf("Write error %v", err)
	}

}

var (
	// watchSignalLoopOnce guards calling the conditionally
	// initialized watchSignalLoop. If watchSignalLoop is non-nil,
	// it will be run in a goroutine lazily once Notify is invoked.
	// See Issue 21576.
	watchSignalLoopOnce sync.Once
	watchSignalLoop     func()
)

// Notify causes package signal to relay incoming signals to c.
// If no signals are provided, all incoming signals will be relayed to c.

package main

func main() {}

// Field accesses through type parameters are disabled
// until we have a more thorough understanding of the
// implications on the spec. See issue #51576.

/*
import "fmt"

type MyStruct struct {
	b1, b2 string
	E
}

type E struct {
	val int
}

type C interface {
	~struct {
		b1, b2 string
		E
	}
}

// run

// Copyright 2018 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.

// Issues 12576 and 12621: Negative untyped floating point constants
// with small magnitude round to 0, not negative zero.

package main

import "math"

var m = -1e-10000

func main() {
	if math.Signbit(m) {
		panic(m)
	}

	ID       string
	PrintFn_ func(string)
}

// Field accesses through type parameters are disabled
// until we have a more thorough understanding of the
// implications on the spec. See issue #51576.
// Use accessor method instead.

func (s StructWithPrinter) PrintFn() func(string) {
	return s.PrintFn_

type PrintShop[T ~string] struct {
	ID       T
	PrintFn_ func(T)
}

// Field accesses through type parameters are disabled
// until we have a more thorough understanding of the
// implications on the spec. See issue #51576.
// Use accessor method instead.

func (s PrintShop[T]) PrintFn() func(T) { return s.PrintFn_ }

func main() {
	PrintWithPrinter(
		"Hello, world.",
		PrintShop[string]{
			ID:       "fake",

// license that can be found in the LICENSE file.

// Field accesses through type parameters are disabled
// until we have a more thorough understanding of the
// implications on the spec. See issue #51576.

package p

type Sf struct {
        f int
}

func f0[P Sf](p P) {
        _ = p.f // ERROR "p.f undefined"
        p.f /* ERROR "p.f undefined" */ = 0
}

func f0t[P ~struct{f int}](p P) {

	// in this ledger.
	SumFn_ func(...K) K
}

// Field accesses through type parameters are disabled
// until we have a more thorough understanding of the
// implications on the spec. See issue #51576.
// Use accessor methods instead.

func (l Ledger[T, _]) ID() T               { return l.ID_ }
func (l Ledger[_, K]) Amounts() []K        { return l.Amounts_ }
func (l Ledger[_, K]) SumFn() func(...K) K { return l.SumFn_ }

// license that can be found in the LICENSE file.

// Field accesses through type parameters are disabled
// until we have a more thorough understanding of the
// implications on the spec. See issue #51576.

package p

// The first example from the issue.
type Numeric interface {
	~int | ~int8 | ~int16 | ~int32 | ~int64
}

// numericAbs matches numeric types with an Abs method.

package main

func main() {}

// Field accesses through type parameters are disabled
// until we have a more thorough understanding of the
// implications on the spec. See issue #51576.

/*
type Sf struct {
	f int
}

func f0[P Sf](p P) {
	_ = p.f
	p.f = 0
}

func f0t[P ~struct{ f int }](p P) {
	_ = p.f
	p.f = 0
}

var _ = f0[Sf]
var _ = f0t[Sf]