示例：

func BenchmarkConcat(b *testing.B) {
    b.Run("StringBuilder", func(b *testing.B) {
        for i := 0; i < b.N; i++ {
            var sb strings.Builder
            sb.WriteString("hello")
            sb.WriteString("world")
            _ = sb.String()
        }
    })

    b.Run("ByteSlice", func(b *testing.B) {
        for i := 0; i < b.N; i++ {
            bs := []byte{}
            bs = append(bs, "hello"...)
            bs = append(bs, "world"...)
            _ = string(bs)
        }
    })
}

示例：测试不同字符串长度下的性能

func BenchmarkStringRepeat(b *testing.B) {
    for _, size := range []int{10, 100, 1000} {
        b.Run(fmt.Sprintf("Size%d", size), func(b *testing.B) {
            s := strings.Repeat("a", size)
            b.ResetTimer()
            for i := 0; i < b.N; i++ {
                _ = strings.ToUpper(s)
            }
        })
    }
}

示例：序列化性能对比

func BenchmarkSerialization(b *testing.B) {
    data := struct{ Name string }{Name: "gopher"}

    b.Run("JSON", func(b *testing.B) {
        for i := 0; i < b.N; i++ {
            bytes, _ := json.Marshal(data)
            _ = bytes
        }
    })

    b.Run("Gob", func(b *testing.B) {
        for i := 0; i < b.N; i++ {
            buf := new(bytes.Buffer)
            enc := gob.NewEncoder(buf)
            enc.Encode(data)
        }
    })
}