On Monday, 19 May 2014 at 17:35:34 UTC, Steven Schveighoffer
wrote:
On Mon, 19 May 2014 13:31:08 -0400, Ola Fosheim Grøstad
<ola.fosheim.grostad+dl...@gmail.com> wrote:
On Monday, 19 May 2014 at 17:11:43 UTC, Steven Schveighoffer
wrote:
It shouldn't matter. Something that returns immutable
references, can return that same thing again if asked the
same way. Nobody should be looking at the address in any
meaningful way.
I think this is at odds with generic programming. What you are
saying is that if you plug a pure function into an algorithm
then you have to test for "pure" in the algorithm if it is
affected by object identity. Otherwise, goodbye plug-n-play.
I think I misstated this, of course, looking at the address for
certain reasons is OK, Object identity being one of them.
immutable(Object*) alloc() pure
{
return new Object();
}
bool oops() pure
{
auto a = alloc();
auto b = alloc();
return a is b;
}
This is a snippet that will always return `true` if memoization
is at work and `false` if strongly pure function will get
actually called twice. If changing result of your program because
of silently enabled compiler optimization does not indicate a
broken compiler I don't know what does.
