Why can I not use the greater than operator with the default key word?

[TylerDM]

Today I tried to do the following as an experiment:

public async Task<bool> CreateAsync(int id)
{
  if (id == default) throw new ArgumentDefaultException(nameof(id));
  if (id < default) throw new ArgumentOutOfRangeException(nameof(id));

  //...
}

But received the following error:

Operator '<' cannot be applied to the operand 'default'

Why is this? I assumed the compiler was replacing default with the equivalent literal value. But if that was the case, this should have worked. Maybe it's an oversight?

[333fred]

The default literal keyword needs to be "target-typed" in order to figure out what type it should represent. We don't have any rules for inferring target-types for one side of an operator like > or < from the other side, so id cannot inform default what type it should be. I would also say that, IMO, this type of code relatively unclear, and it's much better to just use 0.