PFn

为具有≤ 12个参数的函数/闭包在稳定版Rust上提供fn_trait的call、call_mut和call_once。

示例

基本用法

let closure = |x: i32, y: i32, z: String| {
	println!("{}", z);
	x + y
};

// Once the `fn_trait` feature has stabilized, you would do this.
let result = closure.call((5, 42, "Hello World"));

// For now, use PFn.
let result = closure.pfn_call((5, 42, "Hello World"));

泛化不同参数数量的函数

// Here, Func can be a function or closure that takes any number of arguments (actually 1 - 12 arguments).
struct Runnable<Args, Func: PFnOnce<Args>> {
	func: Func,
	args: Args
}
impl<Args, Func: PFnOnce<Args>> Runnable<Args, Func> {
	fn run(self) -> Func::PFnOutput {
		(self.func).pfn_call_once(self.args)
	}
}
let runnable = Runnable {
	func: |mut x: String| {
		x.push_str("!!!");
		x
	},
	args: ("hello world".into(),)
};
assert_eq!(runnable.run(), "hello world!!!");