Bug 2601 – Extraneous cast introduced in member access

I could probably simplify this a bit more, but it's short enough: import std.functional; void next(T)(ref T[] a) { assert(a.length); a = a[1 .. $]; } struct MapRange(alias funAlias, Range) { Range _input; void next() { _input.next; } } template map(fun...) { alias mapImpl!(fun).result map; } template mapImpl(alias fun) { MapRange!(fun, Range) result(Range)(Range input) { return typeof(return)(input); } } unittest { auto x = map!("2 * a")([1, 2, 3, 4, 5]); //auto y = mapImpl!(fun).result!("2 * a")([1, 2, 3, 4, 5]); } The code fails to compile with: Error: cast(int[])this._input is not an lvalue As a bonus, uncommenting the last (albeit incorrect) line in unittest crashes dmd.

The segfault was fixed long ago. Reduced test case also fails on D1. I'm not certain it's a bug, though. -------- void next(ref int[] a) { a[0] = 0; } void bug2601() { int[3] b; next(b); } bug.d(5): Error: cast(int[])b is not an lvalue

I think array literals have become dynamic since then, so the case in comment 1 works. The case in comment 2 does not appear to be a bug, casting a static array to a dynamic array cannot result in an lvalue.