onezero

Did you ever notice the redundancy that’s forced by C#’s syntax for invoking and defining constructors?

using System.Collections.Generic;

class Thing
{
  Thing(int x, int y)
    { ... }

  public static void Main()
  {
     Thing a = new Thing(3,2);
     Dictionary<string,double> b
       = new Dictionary<string,double>();
  }
}

It might be nice if C# added a less redundant syntax.

using System.Collections.Generic;

class Thing2
{
  new(int x, int y)
    { ... }

  public static void Main()
  {
     Thing2 a = new(3,2);
     Dictionary<string,double> b = new();
  }
}

The short form is clearer and less cluttered. Adding it to C# would not require changes to the runtime. (In fact, the ILdAsm disassembler displays at least constructor references as .ctor. This short form does not include the type’s name.)

The long form would still be necessary when an invoked constructor’s including type differs from the type of the object being assigned, or when no type can be inferred from context:

class BaseClass { ... }
class Derived : BaseClass { ... }

class SideEffectConstructorClass
{
  public new()
    { System.Console.WriteLine("hello"); }

  public static void Main()
  {
    BaseClass p = new Derived();
    new SideEffectConstructorClass();
  }
}

Posted on February 25th, 2007 by Andrew
Under C# / Common Language Infrastructure