Swift操作符可以自行定义, 只需要加上简单的标志符即可.
@infix 中置运算. 如+,-,*,/运算
@prefix 前置运算. 如-
@postfix 后置运算. a++, a--
@assignment 赋值运算. +=, -=, --a, ++a
//
// main.swift
// SwiftBasic
//
// Created by yao_yu on 14-7-27.
// Copyright (c) 2014年 yao_yu. All rights reserved.
// import Foundation struct Vector2D{
var x = 0.0, y = 0.0
} @infix func +(a:Vector2D, b:Vector2D) -> Vector2D{
return Vector2D(x: a.x + b.x, y: a.y + b.y)
} @infix func -(a:Vector2D, b:Vector2D) -> Vector2D{
return a + -b
} @prefix func -(a: Vector2D) -> Vector2D{
return Vector2D(x: -a.x, y: -a.y)
} @assignment func += (inout a: Vector2D, b:Vector2D){
a = a + b
} @prefix @assignment func ++(inout a:Vector2D){
++a.x
++a.y
} @postfix func ++(a: Vector2D) -> Vector2D{
return a + Vector2D(x: , y: )
} @infix func ==(a:Vector2D, b:Vector2D) -> Bool{
return (a.x == b.x) && (a.y == b.y)
} @infix func !=(a:Vector2D, b:Vector2D) -> Bool{
return !(a == b)
} func Vector2D_Test(){
var a = Vector2D(x: , y: ), b = Vector2D(x: , y: )
var c = a + b
a += b
println("(\(c.x), \(c.y))")
println("(\(a.x), \(a.y))")
assert(a == c, "a == b失败")
a += b
assert(a != c, "a != b失败")
c = a++
println("(\(a.x), \(a.y))")
println("(\(c.x), \(c.y))")
} Vector2D_Test()