DIP 52 - Implicit conversions

[Simen Kjærås]

On 2013-12-11 22:00, Joseph Rushton Wakeling wrote:
> On 11/12/13 13:44, Simen Kjærås wrote:
>> I've tried to figure out good ways to add some sorely-needed implicit
>> conversions to the language, but I'm sure there are details that need
>> to be
>> ironed out. In other words - destroy!
>
> Since you brought up std.complex: some of the issues here are subtle.
> For example, it's appropriate to allow implicit conversion from
> numerical => Complex (although this can be done fairly readily by just
> calling complex(x) where x is a numerical type); it's also appropriate
> to allow implicit conversion from Imaginary => Complex; but it'd be
> wrong to allow implicit conversion from numerical => Imaginary.

To be honest, I don't find that subtle - it's basic dimensional analysis. :p


> Conversely, I'm not certain whether it'd be appropriate to allow
> implicit conversion Complex => numerical or Complex => Imaginary, even
> if the imaginary or real parts respectively were zero.

I'm certain it would not. At least in my mind, that's almost as bad as 
allowing implicit conversion from string to integer, based on the 
confused notion that it *might* be valid.

--
   Simen