On Friday, 17 August 2012 at 02:25:22 UTC, Jonathan M Davis wrote:
Yeah. It's more than C++, but it's still pretty limited without
pure, and if even with pure, the optimizations can still be
pretty limited.
Yeah, I'm only worried about the language here, not the
implementation.
On Friday, 17 August 2012 at 02:14:22 UTC, Jonathan M Davis wrote:
What I meant is that you know that nothing was altered through
the reference that the getter returned. You don't have any such
guarantee in C++.
I'm not following..
It seems to contradict my second example:
struct MyStruct
{
static int* x;
int y;
this() { }
this(int* z) { x = z; }
auto getValue() const { ++*x; return this.y; }
}
auto s = MyStruct();
s = MyStruct(&s.y);
s.getValue(); // const, but returns 1
s.getValue(); // const, but returns 2
s.getValue(); // const, but returns 3
So unless you're expecting the compiler to have the
implementation for the entire class available in order for it to
be able to do any kind of optimization (in which case, it would
have to do a whole bunch of inference to figure out the aliasing
issues, which would amount to what a C++ could try do just as
well), I'm not seeing where the additional guarantees/potential
optimizations are.
