gopl-zh.github.com/ch4/ch4-04-2.md
2016-02-15 11:06:34 +08:00

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### 4.4.2. 结构体比较
如果结构体的全部成员都是可以比较的,那么结构体也是可以比较的,那样的话两个结构体将可以使用==或!=运算符进行比较。相等比较运算符==将比较两个结构体的每个成员,因此下面两个比较的表达式是等价的:
```Go
type Point struct{ X, Y int }
p := Point{1, 2}
q := Point{2, 1}
fmt.Println(p.X == q.X && p.Y == q.Y) // "false"
fmt.Println(p == q) // "false"
```
可比较的结构体类型和其他可比较的类型一样可以用于map的key类型。
```Go
type address struct {
hostname string
port int
}
hits := make(map[address]int)
hits[address{"golang.org", 443}]++
```