Would like to see ref and out required for function calls

[Jonathan M Davis]

On Thursday, September 13, 2012 12:34:34 Andrei Alexandrescu wrote:
> I don't think there would be problems with allowing ref/out optionally
> at the call site. The thing is, however, that in this matter reasonable
> people may disagree.

I really think that optionally allowing ref and out at the call site is more 
damaging than beneficial. _Requiring_ it could be beneficial, since then you 
know that the arguments are being taken by ref, but if it's optional, it gives 
you a false sense of security and can be misleading. Presumabyl, any time that 
ref or out is used at a call site, presumably the compiler would check that it 
really was passed by ref our out, which would be of some benefit, but it would 
mean _nothing_ if ref or out wasn't used, since it could be an argument being 
passed by ref but which wasn't marked or an argument which wasn't passed by 
ref at all. So, if you have code where ref and out is used at the call site 
semi-religiously, then it'll become very easy to falsely think that the lack 
of them means that ref or out _isn't_ being used when it really is, misleading 
people about what the code is doing.

So, if it wasn't going to break so much code, I'd see some argument for 
changing things so that ref and out were required at the call site, but I 
think that _allowing_ them but not requiring them would actually be 
detrimental.

- Jonathan M Davis