On Wednesday, 12 May 2021 at 13:38:10 UTC, Steven Schveighoffer
wrote:
On 5/12/21 3:28 AM, JG wrote:
Reading the documentation on RefCounted I get the impression
that the following can lead to memory errors. Could someone
explain exactly how that could happen? I suppose that problem
would be the call something to do with front?
```
private struct RefCountedRangeReturnType(R)
{
import std.typecons : RefCounted;
private RefCounted!R r;
auto empty() { return r.refCountedPayload.empty; }
auto front() { return r.refCountedPayload.front; }
void popFront() { r.refCountedPayload.popFront; }
auto save() { return
typeof(this)(RefCounted!R(r.refCountedPayload.save)); }
}
auto refCountedRange(R)(R r)
{
import std.typecons : RefCounted;
return RefCountedRangeReturnType!R(RefCounted!R(r));
}
```
You don't need to access refCountedPayload. RefCounted is
supposed to be like a transparent reference type, and should
forward all calls to the referenced item.
I don't see how you will get memory errors from your code.
Maybe you can elaborate why you think that is?
-Steve
To be honest I can't see the problem. But the following from the
documentation made me wonder if I was doing something that could
lead to memory problems:
"RefCounted is unsafe and should be used with care. No references
to the payload should be escaped outside the RefCounted object."
In particular I wondered if in some special case holding a
reference to front might cause a problem, but perhaps that is
incorrect.
