06-Jul-2013 22:54, TommiT пишет:
On Saturday, 6 July 2013 at 18:07:08 UTC, Dicebot wrote:
On Saturday, 6 July 2013 at 15:38:45 UTC, Artur Skawina wrote:
Do you think this would be a problem /in practice/?
Yes. Honestly, lot of problems. I can easily imagine template function
that modifies its argument in-place for a mutable qualifier and
allocates a copy for an immutable one. Templates that introspect their
parameter type to format some string. Different algorithms for
processing mutable and immutable versions of same container.
He's talking about changing the semantics only on POD types, like int,
struct of ints, static array of ints... only types that can implicitly
convert from immutable to mutable.
I've seen an aggressive proposal back in the day to just do a shallow
unqual on all aggregates passed by value.
And it is not just code breakage - you propose some magic instead of
simple well-defined semantics and so far I don't even see the detailed
description how new system should behave.
As I understand it, it would be like what C++ does, but only for POD
types. Just take const, immutable, whatever away when they're passed by
value.
--
Dmitry Olshansky
