[Mono-list] offtopic, but cool

[Lluis Sanchez]

System.Drawing.Rectangle is a struct, so it is copied by value, not by
reference.

On dc, 2004-05-12 at 14:41, Cesar Mello wrote:
> Hi Cory,
> 
> In the C++ sample, you are passing the rect by value, so you are
> saving a copy in the list. In C# a reference to the object is used, so
> there is no copy-construction overhead.
> 
> You can change the list<rect> to a list<rect*>, but this way you have
> to manage the memory by yourlself. 
> 
> []
> Mello
> 
> 
> 
> Cory Nelson wrote:
> > Just got done installing the VS.NET 2005 preview and did a small test.
> > 
> > I compared an ArrayList of Rectangles to a List<Rectangle>, and timed
> > inserting 1mil rects into each.  I also wrote an equivalent c++ app. 
> > Got some interesting results:
> > 
> > ArrayList: 265ms
> > List<Rectangle>: 62ms
> > list<rect>: 141ms
> > 
> > So it seems with generics .NET is finally faster than c++ (at least,
> > in this case).
> > 
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> >   
> > 
> > ____________________________________________________________________
> > #region Using directives
> > 
> > using System;
> > using System.Collections;
> > using System.Collections.Generic;
> > using System.Drawing;
> > 
> > #endregion
> > 
> > namespace SpeedTest {
> > 	class Program {
> > 		static void Main(string[] args) {
> > 			ArrayList al = new ArrayList();
> > 			List<Rectangle> rl = new List<Rectangle>();
> > 			DateTime start, end;
> > 
> > 			GC.Collect();
> > 			GC.WaitForPendingFinalizers();
> > 
> > 			start = DateTime.Now;
> > 			for (int i = 0; i < 1000000; i++)
> > 				al.Add(new Rectangle(i, i, i, i));
> > 			end = DateTime.Now;
> > 
> > 			Console.WriteLine("Arraylist:       {0:F3}ms", (end-start).TotalMilliseconds);
> > 
> > 			GC.Collect();
> > 			GC.WaitForPendingFinalizers();
> > 
> > 			start = DateTime.Now;
> > 			for (int i = 0; i < 1000000; i++)
> > 				rl.Add(new Rectangle(i, i, i, i));
> > 			end = DateTime.Now;
> > 
> > 			Console.WriteLine("List<Rectangle>:  {0:F3}ms", (end - start).TotalMilliseconds);
> > 		}
> > 	}
> > }
> > 
> >   
> > 
> > ____________________________________________________________________
> > #include <list>
> > #include <iostream>
> > #include <ctime>
> > using namespace std;
> > 
> > struct rect {
> > 	int x;
> > 	int y;
> > 	int width;
> > 	int height;
> > };
> > 
> > int main(void) {
> > 	list<rect> rl;
> > 
> > 	clock_t start=clock();
> > 	for(int i=0; i<1000000; i++) {
> > 		rect r={i, i, i, i};
> > 		rl.push_back(r);
> > 	}
> > 	clock_t end=clock();
> > 
> > 	cout << "list<rect>: " << (((float)(end-start))/((float)CLOCKS_PER_SEC)*1000.0f) << "ms" << endl;
> > 
> > 	return 0;
> > }
> > 
> >   
>