https://issues.dlang.org/show_bug.cgi?id=23598
Issue ID: 23598
Summary: Another nasty forward reference bug
Product: D
Version: D2
Hardware: All
OS: All
Status: NEW
Keywords: rejects-valid
Severity: blocker
Priority: P1
Component: dmd
Assignee: [email protected]
Reporter: [email protected]
This one took me a long time to reduce. Marking it as a blocker, as I haven't
found an acceptable workaround yet.
----
alias aliases(a...) = a;
template sort(alias f, a...)
{
static if (a.length > 0) // (1)
{
alias x = f!(a[1]);
alias sort = a;
}
else
alias sort = a;
}
alias SortedItems = sort!(isDependencyOf, Top, String); // (2)
pragma (msg, "1: ", SortedItems);
enum isDependencyOf(Item) = Item.DirectDependencies.length == 0;
struct Top
{
alias DirectDependencies = aliases!();
}
struct String
{
alias DirectDependencies = aliases!();
pragma(msg, "2: ", SortedItems);
enum l = SortedItems.length; // (3)
static assert(is(typeof(SortedItems.length) == size_t)); // (4)
}
----
Error: no property `length` for `sort!(isDependencyOf, Top, String)` of type
`void`
The SortedItems tuple at (2) is (Top, String), which is correct, but at (3) it
is broken. However, at (4) it is correct again - the assert passes if (3) is
commented out. This may have something to do with the 'static if' at (1), as
the error goes away if the 'static if' and the 'else' branch are commented out.
--
