**Haxe 3.1.0 以后** > **Since Haxe 3.1.0** 如果一个构造函数声明为 内联（第4.4.2），编译器在某些情况下会尝试优化它。有下面几个需要： > If a constructor is declared to be inline (4.4.2), the compiler may try to optimize it away in certain situations. There are several requirements for this to work: * 构造函数调用的结果必须直接分配到一个局部变量 * 构造函数字段的表达式必须只包含给它的字段的赋值。 > * The result of the constructor call must be directly assigned to a local variable. > * The expression of the constructor field must only contain assignments to its fields. 下面的例子演示了内联构造函数： > The following example demonstrates constructor inlining: ~~~ class Point { public var x:Float; public var y:Float; public inline function new(x:Float, y:Float) { this.x = x; this.y = y; } } class Main { static public function main() { var pt = new Point(1.2, 9.3); } } ~~~ 看一下JavaScript的输出，揭示了效果： > A look at the JavaScript output reveals the effect: ~~~ Main.main = function() { var pt_x = 1.2; var pt_y = 9.3; }; ~~~