1// run
2
3// Copyright 2022 The Go Authors. All rights reserved.
4// Use of this source code is governed by a BSD-style
5// license that can be found in the LICENSE file.
6
7package main
8
9import (
10	"log"
11	"reflect"
12	"sort"
13)
14
15func main() {
16	const length = 257
17	x := make([]int64, length)
18	for i := 0; i < length; i++ {
19		x[i] = int64(i) * 27644437 % int64(length)
20	}
21
22	isLessStatic := func(i, j int) bool {
23		return x[i] < x[j]
24	}
25
26	isLessReflect := reflect.MakeFunc(reflect.TypeOf(isLessStatic), func(args []reflect.Value) []reflect.Value {
27		i := args[0].Int()
28		j := args[1].Int()
29		b := x[i] < x[j]
30		return []reflect.Value{reflect.ValueOf(b)}
31	}).Interface().(func(i, j int) bool)
32
33	sort.SliceStable(x, isLessReflect)
34
35	for i := 0; i < length-1; i++ {
36		if x[i] >= x[i+1] {
37			log.Fatalf("not sorted! (length=%v, idx=%v)\n%v\n", length, i, x)
38		}
39	}
40}
41