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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>
73 lines
1.6 KiB
Go
73 lines
1.6 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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"reflect"
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)
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type Number interface {
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~int | ~int8 | ~int16 | ~int32 | ~int64 | ~uint | ~uint8 | ~uint16 | ~uint32 | ~uint64 | ~uintptr | ~float32 | ~float64
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}
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type MySlice []int
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type MyFloatSlice []float64
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type _SliceOf[E any] interface {
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type []E
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}
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func _DoubleElems[S _SliceOf[E], E Number](s S) S {
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r := make(S, len(s))
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for i, v := range s {
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r[i] = v + v
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}
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return r
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}
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// Test use of untyped constant in an expression with a generically-typed parameter
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func _DoubleElems2[S _SliceOf[E], E Number](s S) S {
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r := make(S, len(s))
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for i, v := range s {
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r[i] = v * 2
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}
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return r
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}
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func main() {
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arg := MySlice{1, 2, 3}
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want := MySlice{2, 4, 6}
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got := _DoubleElems[MySlice, int](arg)
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if !reflect.DeepEqual(got, want) {
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panic(fmt.Sprintf("got %s, want %s", got, want))
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}
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// constraint type inference
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got = _DoubleElems[MySlice](arg)
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if !reflect.DeepEqual(got, want) {
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panic(fmt.Sprintf("got %s, want %s", got, want))
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}
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got = _DoubleElems(arg)
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if !reflect.DeepEqual(got, want) {
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panic(fmt.Sprintf("got %s, want %s", got, want))
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}
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farg := MyFloatSlice{1.2, 2.0, 3.5}
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fwant := MyFloatSlice{2.4, 4.0, 7.0}
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fgot := _DoubleElems(farg)
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if !reflect.DeepEqual(fgot, fwant) {
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panic(fmt.Sprintf("got %s, want %s", fgot, fwant))
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}
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fgot = _DoubleElems2(farg)
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if !reflect.DeepEqual(fgot, fwant) {
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panic(fmt.Sprintf("got %s, want %s", fgot, fwant))
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}
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}
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