[swift-evolution] Reconsidering SE-0003 Removing var from Function Parameters and Pattern Matching

[Joe Groff]

> On Jan 28, 2016, at 12:43 AM, Brent Royal-Gordon <brent at architechies.com> wrote:
> 
>> We have a lot of evidence that 'if var' confuses people—a lot of users think that 'if var' and 'var' bindings in case patterns will write back to the original value when this isn't the case.
> 
> Can we address this with a diagnostic?
> 
> 	var bar: Int? = 1
> 	if var foo = bar {
> 		foo += 1	// Warning: Value is never used after modification (foo is a copy, not an alias)
> 	}
> 	print(bar)

Good idea.

-Joe