D's "accessors" are like abusing operator overloads

[BCS]

Hello Nick,

> I don't mean to put words in the Tango crew's mouths, but IMO this
> piece from 0.99.8's changelog is a great demonstration of what's wrong
> with D's sloppy "accessor" syntax:
> 
> -------------
> tango.time
> * TimeSpan.seconds(ulong), etc. is now replaced by
> TimeSpan.fromSeconds(ulong), etc. The original form causes problems
> when people write code like:
> 
> auto ts = TimeSpan.seconds(60);
> ts.seconds = 30; // you would think this would assign 30 seconds to
> ts, but
> what it does is create a
> // temporary and throw it away.
> -------------
> The fact that D lets you freely switch between "foo(x)" and "foo = x"
> (at least when you're not using a return value from foo) implies that
> passing one argument to a function is, in the general case,
> conceptually related to assigning a value. And that is an absurdity
> and abuse of syntax on the same level as pretending that string
> concatenation is an "addition" or that outputting is a "<<", etc.
> 
> And this "solution" that Tango was forced to use as a result of that
> kludge doesn't totally solve the problem since it leaves symantic
> gibberish like this as perfectly-compileable:
> 
> ts.fromSeconds = 30; // WTF is that supposed to mean?!? But it
> compiles anyway!
> 

One option would be to only allow that fn = v syntax where fn returns void.