Question

Instead of writing

 int i = new int();
 i = 7; 

One can write

int i = 7; 

Is there a way I can get that style of initialisation for my own types?

MyType mt = xyz; 

Answer 1

The closest you can come is by creating implicit conversions on your type. For example:

public class Unit
{
  public static implicit operator Unit( string val )
  {
     return Unit.Parse( val );
  }

  public static Unit Parse( string unitString )
  {
    // parsing magic goes here
  }
}

This would enable you to do something like this:

Unit width = "150px";
var width = Unit.Parse("150px"); // equivalent to previous line

Note that you cannot introduce new syntax; this would be impossible to implement:

Unit width = 150px;

since 150px does not represent a valid value type.

Note that implicit casting can get you into trouble in weird ways so don’t over do it. Support implicit casting only to and from types that you’re really going to need.

Alternatively, if you’re using C# compiler 3.5 or up you can also use inline initialization which is more verbose but also more explicit:

Unit with = new { Value=150, UnitType=Units.Pixel };