mirror of
https://github.com/golang/go
synced 2024-11-17 20:44:47 -07:00
e24977d231
The next CL will remove the -G flag, effectively hard-coding it to its current default (-G=3). Change-Id: Ib4743b529206928f9f1cca9fdb19989728327831 Reviewed-on: https://go-review.googlesource.com/c/go/+/388534 Reviewed-by: Keith Randall <khr@golang.org> Trust: Matthew Dempsky <mdempsky@google.com> Run-TryBot: Matthew Dempsky <mdempsky@google.com> TryBot-Result: Gopher Robot <gobot@golang.org>
73 lines
1.5 KiB
Go
73 lines
1.5 KiB
Go
// run
|
|
|
|
// Copyright 2021 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
|
|
|
|
import (
|
|
"fmt"
|
|
"reflect"
|
|
)
|
|
|
|
type Number interface {
|
|
~int | ~int8 | ~int16 | ~int32 | ~int64 | ~uint | ~uint8 | ~uint16 | ~uint32 | ~uint64 | ~uintptr | ~float32 | ~float64
|
|
}
|
|
|
|
type MySlice []int
|
|
type MyFloatSlice []float64
|
|
|
|
type _SliceOf[E any] interface {
|
|
~[]E
|
|
}
|
|
|
|
func _DoubleElems[S _SliceOf[E], E Number](s S) S {
|
|
r := make(S, len(s))
|
|
for i, v := range s {
|
|
r[i] = v + v
|
|
}
|
|
return r
|
|
}
|
|
|
|
// Test use of untyped constant in an expression with a generically-typed parameter
|
|
func _DoubleElems2[S _SliceOf[E], E Number](s S) S {
|
|
r := make(S, len(s))
|
|
for i, v := range s {
|
|
r[i] = v * 2
|
|
}
|
|
return r
|
|
}
|
|
|
|
func main() {
|
|
arg := MySlice{1, 2, 3}
|
|
want := MySlice{2, 4, 6}
|
|
got := _DoubleElems[MySlice, int](arg)
|
|
if !reflect.DeepEqual(got, want) {
|
|
panic(fmt.Sprintf("got %s, want %s", got, want))
|
|
}
|
|
|
|
// constraint type inference
|
|
got = _DoubleElems[MySlice](arg)
|
|
if !reflect.DeepEqual(got, want) {
|
|
panic(fmt.Sprintf("got %s, want %s", got, want))
|
|
}
|
|
|
|
got = _DoubleElems(arg)
|
|
if !reflect.DeepEqual(got, want) {
|
|
panic(fmt.Sprintf("got %s, want %s", got, want))
|
|
}
|
|
|
|
farg := MyFloatSlice{1.2, 2.0, 3.5}
|
|
fwant := MyFloatSlice{2.4, 4.0, 7.0}
|
|
fgot := _DoubleElems(farg)
|
|
if !reflect.DeepEqual(fgot, fwant) {
|
|
panic(fmt.Sprintf("got %s, want %s", fgot, fwant))
|
|
}
|
|
|
|
fgot = _DoubleElems2(farg)
|
|
if !reflect.DeepEqual(fgot, fwant) {
|
|
panic(fmt.Sprintf("got %s, want %s", fgot, fwant))
|
|
}
|
|
}
|