Recenty I've been trying to figure out how to turn a TypeReference into a Type in Cecil. The reason is that I'm taking a bunch of values and putting them together via a StringBuilder, like this:

var random = new Random();
var id = Guid.NewGuid();
var one = 1;
var data = "data";

var builder = new StringBuilder();
builder.Append(one).Append(data)
   .Append(random).Append(id);

But trying to find the version of Append() that most closely matches a particular type in Cecil isn't easy:

var append = @this.Module.Import(typeof(StringBuilder)
   .GetMethod("Append", 
      new Type[] { ConvertToType(property.PropertyType) })); 

In that code, I have a TypeReference via PropertyType, and I want to find the Append() method via a call to GetMethod(), which requires a Type. ConvertToType() is a mythical method that I don't have yet, which would convert the TypeReference to a Type.

Now, someone on the thread made a comment basically asking "why would I want to do this?", pointing to the fact that most of the Append() methods just end up calling ToString() anyway. So he's basically saying, why don't I emit code like this:

var random = new Random();
var id = Guid.NewGuid();
var one = 1;
var data = "data";

var builder = new StringBuilder();
   builder.Append(one.ToString()).Append(data)
      .Append(random.ToString()).Append(id.ToString());

I haven't tried to emit this with Cecil yet, but I'm thinking this might be easier. I do have to do some boxing of the value types to call ToString() on them correctly, but that shouldn't be too hard. There's also another option: cast everything to object and just call that one version of Append():

var random = (object)(new Random());
var id = (object)Guid.NewGuid();
var one = (object)1;
var data = (object)"data";

for(var i = 0; i < Program.Iterations; i++)
{
   var builder = new StringBuilder();
   builder.Append(one).Append(data)
      .Append(random).Append(id);
}

I was curious, though...is there a performance difference between these approaches?

SpecificTypes: 9.284

ToString: 9.506

AllObjects: 9.423

These are the results of running each approach 90 million times, and then running the test 3 times. Basically...I don't see a huge difference between any of them, so I'm going to explore calling ToString() on them as that may be the best way to do this in Cecil. From a language perspective, I definitely like the first way as it looks much cleaner to me, but I'm emitting code in this case so aesthetics isn't really important!

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