d可变模板处理事件

import std.stdio;
struct Event(T...)
{
    void function(T)[] listeners;
    void addListener(void function(T) handler)
    {
        listeners ~= handler;
    }
    void emit(T args)
    {
        foreach (listener; listeners)
        {
            listener(args);
        }
    }
}

void onResize(uint newWidth, uint newHeight)
{
    writefln("Resized: %d %d", newWidth, newHeight);
}

void main()
{
    Event!(uint, uint) windowResizeEvent;
    windowResizeEvent.addListener(&onResize);
    windowResizeEvent.emit(1000, 2000);
}