https://issues.dlang.org/show_bug.cgi?id=24465
Issue ID: 24465
Summary: Tuple does not get a copy constructor when its members
need it
Product: D
Version: D2
Hardware: All
OS: All
Status: NEW
Severity: normal
Priority: P1
Component: phobos
Assignee: [email protected]
Reporter: [email protected]
An example:
---
import std.typecons;
void main()
{
Tuple!(int, S) t;
foo(t);
}
struct S
{
int i;
this(ref return scope inout(S) rhs) scope @trusted inout pure nothrow
{
this.i = rhs.i;
}
}
void foo(Tuple!(int, S))
{
}
---
It fails with
---
bug.d(6): Error: function `foo` is not callable using argument types
`(Tuple!(int, S))`
bug.d(6): `struct Tuple` does not define a copy constructor for
`Tuple!(int, S)` to `Tuple!(int, S)` copies
bug.d(19): `bug.foo(Tuple!(int, S))` declared here
---
I _think_ that the problem is that this constructor
---
this(U)(U another)
if (areBuildCompatibleTuples!(typeof(this), U))
{
field[] = another.field[];
}
---
is managing to serve as an rvalue constructor, which unfortunately, is
incompatible with copy constructors (I'm not convinced that it should be, but
it is). But regardless of what the exact reason that it's currently failing is,
it should work to create and copy Tuples which contain types with copy
constructors.
--
