go/test/typeparam/index.go
Dan Scales 8767b87ab5 [dev.typeparams] cmd/compile: functions to create GC shape types/names for a concrete type
Created functions to create GC shape type and names, based on a proposal
from Keith. Kept unsigned and signed integer types as different, since
they have different shift operations.

Included adding in alignment fields where padding is
required between fields, even though that seems like it will be fairly
uncommon to use.

Added some extra unusual struct typeparams (for testing the gcshape
names/types) in index.go test.

Change-Id: I8132bbd28098bd933435b8972ac5cc0b39f4c0df
Reviewed-on: https://go-review.googlesource.com/c/go/+/329921
Trust: Dan Scales <danscales@google.com>
Run-TryBot: Dan Scales <danscales@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2021-06-30 20:51:17 +00:00

83 lines
1.6 KiB
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
}
type obj2 struct {
x int8
y float64
}
type obj3 struct {
x int64
y int8
}
type inner struct {
y int64
z int32
}
type obj4 struct {
x int32
s inner
}
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))
}
vec4 := []obj2{obj2{2, 3.0}, obj2{3, 4.0}, obj2{4, 5.0}}
if got := Index(vec4, vec4[2]); got != want {
panic(fmt.Sprintf("got %d, want %d", got, want))
}
vec5 := []obj3{obj3{2, 3}, obj3{3, 4}, obj3{4, 5}}
if got := Index(vec5, vec5[2]); got != want {
panic(fmt.Sprintf("got %d, want %d", got, want))
}
vec6 := []obj4{obj4{2, inner{3, 4}}, obj4{3, inner{4, 5}}, obj4{4, inner{5, 6}}}
if got := Index(vec6, vec6[2]); got != want {
panic(fmt.Sprintf("got %d, want %d", got, want))
}
}