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5355753009
We don't usually reformat the test directory, but all of the files in test/typeparam are syntactically valid. I suspect the misformattings here are because developers aren't re-installing gofmt with -tags=typeparams, not intentionally exercising non-standard formatting. Change-Id: I3767d480434c19225568f3c7d656dc8589197183 Reviewed-on: https://go-review.googlesource.com/c/go/+/338093 Trust: Matthew Dempsky <mdempsky@google.com> Trust: Robert Griesemer <gri@golang.org> Run-TryBot: Matthew Dempsky <mdempsky@google.com> TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Robert Griesemer <gri@golang.org>
65 lines
1.5 KiB
Go
65 lines
1.5 KiB
Go
// run -gcflags=-G=3
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// Copyright 2021 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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package main
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import (
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"fmt"
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)
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type Gen[A any] func() (A, bool)
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func Combine[T1, T2, T any](g1 Gen[T1], g2 Gen[T2], join func(T1, T2) T) Gen[T] {
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return func() (T, bool) {
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var t T
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t1, ok := g1()
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if !ok {
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return t, false
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}
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t2, ok := g2()
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if !ok {
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return t, false
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}
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return join(t1, t2), true
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}
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}
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type Pair[A, B any] struct {
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A A
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B B
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}
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func _NewPair[A, B any](a A, b B) Pair[A, B] {
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return Pair[A, B]{a, b}
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}
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func Combine2[A, B any](ga Gen[A], gb Gen[B]) Gen[Pair[A, B]] {
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return Combine(ga, gb, _NewPair[A, B])
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}
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func main() {
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var g1 Gen[int] = func() (int, bool) { return 3, true }
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var g2 Gen[string] = func() (string, bool) { return "x", false }
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var g3 Gen[string] = func() (string, bool) { return "y", true }
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gc := Combine(g1, g2, _NewPair[int, string])
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if got, ok := gc(); ok {
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panic(fmt.Sprintf("got %v, %v, wanted -/false", got, ok))
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}
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gc2 := Combine2(g1, g2)
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if got, ok := gc2(); ok {
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panic(fmt.Sprintf("got %v, %v, wanted -/false", got, ok))
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}
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gc3 := Combine(g1, g3, _NewPair[int, string])
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if got, ok := gc3(); !ok || got.A != 3 || got.B != "y" {
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panic(fmt.Sprintf("got %v, %v, wanted {3, y}, true", got, ok))
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}
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gc4 := Combine2(g1, g3)
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if got, ok := gc4(); !ok || got.A != 3 || got.B != "y" {
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panic(fmt.Sprintf("got %v, %v, wanted {3, y}, true", got, ok))
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}
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}
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