go/test/typeparam/index.go
Dan Scales c0aa7bd760 [dev.typeparams] cmd/compile: small fixes for stenciling
- Create the stencil name using targ.Type.String(), which handles cases
   where, for example, a type argument is a pointer to a named type,
   etc. *obj.

 - Set name.Def properly for a new stenciled func (have the symbol point
   back to the associated function node).  Will be required when exporting.

 - Add missing copying of Func field when making copies of Name nodes.
   (On purpose (it seems), Name nodes don't have a copy() function, so
   we have to copy all the needed fields explicitly.)

 - Deal with nil type in subster.node(), which is the type of the return
   value for a function that doesn't return anything.

 - Fix min to match standard want/go form, and add in float tests.  Changed
   Got -> got in bunch of other typeparam tests.

 - Add new tests index.go, settable.go, and smallest.go (similar to
   examples in the type param proposal), some of which need the above
   changes.

Change-Id: I09a72302bc1fd3635a326da92405222afa222e85
Reviewed-on: https://go-review.googlesource.com/c/go/+/291109
Trust: Dan Scales <danscales@google.com>
Trust: Robert Griesemer <gri@golang.org>
Run-TryBot: Dan Scales <danscales@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
2021-02-11 21:46:39 +00:00

46 lines
941 B
Go

// run -gcflags=-G=3
// 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"
)
// Index returns the index of x in s, or -1 if not found.
func index[T comparable](s []T, x T) int {
for i, v := range s {
// v and x are type T, which has the comparable
// constraint, so we can use == here.
if v == x {
return i
}
}
return -1
}
type obj struct {
x int
}
func main() {
want := 2
vec1 := []string{"ab", "cd", "ef"}
if got := index(vec1, "ef"); got != want {
panic(fmt.Sprintf("got %d, want %d", got, want))
}
vec2 := []byte{'c', '6', '@'}
if got := index(vec2, '@'); got != want {
panic(fmt.Sprintf("got %d, want %d", got, want))
}
vec3 := []*obj{&obj{2}, &obj{42}, &obj{1}}
if got := index(vec3, vec3[2]); got != want {
panic(fmt.Sprintf("got %d, want %d", got, want))
}
}