How do I create an inout object with template parameters?
Take following code:
import std.stdio;
import std.traits;
struct S
{
int[] arr;
}
interface I
{
inout(I) opIndex(size_t idx) inout;
}
class Test(T) : I
{
// Error: variable
`onlineapp.Test!(inout(int)[]).Test.member` only parameters or
stack based variables can be inout
T member;
this(inout T mem) inout
{
this.member = mem;
}
inout(Test!T) get() inout
{
return new inout Test!(Unqual!(typeof(member)))(member);
}
inout(I) opIndex(size_t idx) inout
{
switch (idx)
static foreach (index, t; T.tupleof)
{
case index:
// Error: template
instance `onlineapp.Test!(inout(int)[])` error instantiating
return new inout
Test!(Unqual!(typeof(this.member.tupleof[index])))
(this.member.tupleof[index]);
default:
return null;
}
}
}
unittest
{
auto s = S([1,2,3]);
auto t = new const Test!S(s);
}
`Unqual` in this case just turns `inout(int[])` into
`inout(int)[]`, which is why it complains. That's a side effect
of this example, however the main question is how one would go
about achieving something like this idiomatically?
I would like to return a new object and that object should have
the same mutability as the one creating it.