Missing compiler warning?

[Chris]

On Sunday, 20 October 2013 at 01:15:12 UTC, Jonathan M Davis 
wrote:
> On Saturday, October 19, 2013 18:50:16 Chris wrote:
>> A warning would be enough. The thing is I didn't want to give 
>> it
>> the same name. It was meant to be the class variable but the 
>> auto
>> was a leftover from a test. A warning would have been nice, à 
>> la
>> "do you really want this?". I would have seen it immediately.
>
> Warnings are pretty much always a bad idea IMHO. If you're 
> being a responsible
> programmer, you fix all warnings, so they're ultimately not 
> really any different
> from an error except that you can leave them alone temporarily 
> while
> developing. It's far better to make something an error not have 
> the compiler
> complain about it at all. lint-like tools can do additional 
> analysis based on
> additional stuff that a programmer decides they want to look 
> for in their code,
> but the compiler shouldn't be pointing out stuff that "might" 
> be wrong, because
> you'll have to "fix" it whether it's wrong or not just to get 
> the compiler to
> shut up about it.
>
> And Walter agrees with me on this. Pretty much the only reason 
> that warnings
> even exist in dmd is because he got pestered into adding them, 
> and even then,
> we don't have very many. Most of them end up being warnings 
> about stuff that
> will become errors later (rather than just making them an error 
> immediately
> and break code).
>
> - Jonathan M Davis

I can see your point. However, in this case a warning would 
really make sense, in my opinion, because it is potentially 
harmful and very likely not what the programmer intended, except 
in a case like

this (string a) {
  this.a = a;
}

which could be ignored by the compiler. Usually same-name 
variables are only used in the constructor. Using them in other 
places in the class is not recommendable, and I don't mind useful 
warnings like "Listen, there is a variable shadowing the class 
variable, do you really really want this?" To spam the command 
line with compiler warnings is not very helpful, I agree, but is 
it a good solution to categorically rule out warnings?