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// Copyright 2016 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 reflectutil
import (
"fmt"
"reflect"
"strconv"
"testing"
)
func TestSwapper(t *testing.T) {
type I int
var a, b, c I
type pair struct {
x, y int
}
type pairPtr struct {
x, y int
p *I
}
type S string
tests := []struct {
in interface{}
i, j int
want interface{}
}{
{
in: []int{1, 20, 300},
i: 0,
j: 2,
want: []int{300, 20, 1},
},
{
in: []uintptr{1, 20, 300},
i: 0,
j: 2,
want: []uintptr{300, 20, 1},
},
{
in: []int16{1, 20, 300},
i: 0,
j: 2,
want: []int16{300, 20, 1},
},
{
in: []int8{1, 20, 100},
i: 0,
j: 2,
want: []int8{100, 20, 1},
},
{
in: []*I{&a, &b, &c},
i: 0,
j: 2,
want: []*I{&c, &b, &a},
},
{
in: []string{"eric", "sergey", "larry"},
i: 0,
j: 2,
want: []string{"larry", "sergey", "eric"},
},
{
in: []S{"eric", "sergey", "larry"},
i: 0,
j: 2,
want: []S{"larry", "sergey", "eric"},
},
{
in: []pair{{1, 2}, {3, 4}, {5, 6}},
i: 0,
j: 2,
want: []pair{{5, 6}, {3, 4}, {1, 2}},
},
{
in: []pairPtr{{1, 2, &a}, {3, 4, &b}, {5, 6, &c}},
i: 0,
j: 2,
want: []pairPtr{{5, 6, &c}, {3, 4, &b}, {1, 2, &a}},
},
}
for i, tt := range tests {
inStr := fmt.Sprint(tt.in)
Swapper(tt.in)(tt.i, tt.j)
if !reflect.DeepEqual(tt.in, tt.want) {
t.Errorf("%d. swapping %v and %v of %v = %v; want %v", i, tt.i, tt.j, inStr, tt.in, tt.want)
}
}
}
func BenchmarkSwap(b *testing.B) {
const N = 1024
strs := make([]string, N)
for i := range strs {
strs[i] = strconv.Itoa(i)
}
swap := Swapper(strs)
b.ResetTimer()
i, j := 0, 1
for n := 0; n < b.N; n++ {
i = (i + 1) % N
j = (j + 2) % N
swap(i, j)
}
}
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