Swift 自定义运算符 ++ -- **
extension Int {
static prefix func ++ (left:inout Int) -> Int{
left += 1;
return left;
}
}
extension Int {
static postfix func ++ (left:inout Int) -> Int{
left += 1;
return left - 1;
}
}
prefix operator &++
extension Int {
static prefix func &++ (left:inout Int) -> Int{
left &+= 1;
return left;
}
}
postfix operator &++
extension Int {
static postfix func &++ (left:inout Int) -> Int{
left &+= 1;
return left &- 1;
}
}
extension Int {
static prefix func -- (left:inout Int) -> Int{
left -= 1;
return left;
}
}
extension Int {
static postfix func -- (left:inout Int) -> Int{
left -= 1;
return left + 1;
}
}
prefix operator &--
extension Int {
static prefix func &-- (left:inout Int) -> Int{
left &-= 1;
return left;
}
}
postfix operator &--
extension Int {
static postfix func &-- (left:inout Int) -> Int{
left &-= 1;
return left &+ 1;
}
}
infix operator ** : MultiplicationPrecedence
extension Int {
static func ** (left:Int, right:Int) -> Int{
var result = 1;
for _ in 0..<right {
result *= left;
}
return result;
}
}
infix operator &** : MultiplicationPrecedence
extension Int {
static func &** (left:Int, right:Int) -> Int{
var result = 1;
for _ in 0..<right {
result &*= left;
}
return result;
}
}
测试结果：
var a = 10
print(a++)
print(a)
a = 10
print(++a)
print(a)
a = 10
print(a--)
print(a)
a = 10
print(--a)
print(a)
a = 10
print(a ** 10)
a = Int.max
print(a&++)
print(a)
a = Int.max
print(&++a)
print(a)
a = Int.min
print(a&--)
print(a)
a = Int.min
print(&--a)
print(a)
a = 2
print(2 &** 63)
运行结果：
10
11
11
11
10
9
9
9
10000000000
9223372036854775807
-9223372036854775808
-9223372036854775808
-9223372036854775808
-9223372036854775808
9223372036854775807
9223372036854775807
9223372036854775807
-9223372036854775808
