Bug 19444 – hasRawAliasing loops on class with static array, cannot swap class refs

The following code used to work but now fails to compile: import std.algorithm : swap; class Thing { Thing[2] child; this() { } static Thing bug(Thing l, Thing r) { swap(l,r); return l; } } DMD 2.081.2 correctly accepts and compiles this code. DMD 2.083.0 outputs these errors: /home/kirsybuu/.dvm/compilers/dmd-2.083.0/linux/bin/../../src/phobos/std/traits.d(2890): Error: forward reference of variable hasRawAliasing /home/kirsybuu/.dvm/compilers/dmd-2.083.0/linux/bin/../../src/phobos/std/traits.d(2902): Error: template instance `std.traits.hasRawAliasing!(Thing).Impl!(Thing[2])` error instantiating /home/kirsybuu/.dvm/compilers/dmd-2.083.0/linux/bin/../../src/phobos/std/traits.d(3233): instantiated from here: hasRawAliasing!(Thing) /home/kirsybuu/.dvm/compilers/dmd-2.083.0/linux/bin/../../src/phobos/std/algorithm/mutation.d(2744): instantiated from here: hasAliasing!(Thing) swap_hasRawAliasing.d(6): instantiated from here: swap!(Thing) Failed: ["/home/kirsybuu/.dvm/compilers/dmd-2.083.0/linux/bin/dmd", "-v", "-o-", "swap_hasRawAliasing.d", "-I."] The only code in the backtrace that seems to be different between versions is hasRawAliasing, which added the following case that is causing a recursive loop: else static if (is(T[0] foo : U[N], U, size_t N)) enum has = hasRawAliasing!U; Also, given that I just want to swap two class references, I would expect them to be handled similarly to pointers: changing Thing to a struct and l/r to Thing* makes DMD 2.083.0 accept the code.

PR: https://github.com/dlang/phobos/pull/6784

Commits pushed to master at https://github.com/dlang/phobos https://github.com/dlang/phobos/commit/43545feff89de12b77d5c489b93a805dc2a77a50 Fix Issue 19444. https://github.com/dlang/phobos/commit/807afdc85ea77ada608b36f8d0852f9728531b1b Merge pull request #6784 from radcapricorn/fix19444 Fix Issue 19444: hasRawAliasing loops on class with static array