Bug 12733 – parallelism.amap incorrect assignment without initialization

This code from Rosettacode fails in 2.065: //---- ulong[] decompose(ulong n) pure nothrow { typeof(return) result; for (ulong i = 2; n >= i * i; i++) for (; n % i == 0; n /= i) result ~= i; if (n != 1) result ~= n; return result; } void main() { import std.stdio, std.algorithm, std.parallelism, std.typecons; immutable ulong[] data = [ 2UL^^59-1, 2UL^^59-1, 2UL^^59-1, 112_272_537_195_293UL, 115_284_584_522_153, 115_280_098_190_773, 115_797_840_077_099, 112_582_718_962_171, 112_272_537_095_293, 1_099_726_829_285_419]; //auto factors = taskPool.amap!(n => tuple(decompose(n), n))(data); //static enum genPair = (ulong n) pure => tuple(decompose(n), n); static genPair(ulong n) pure { return tuple(decompose(n), n); } auto factors = taskPool.amap!genPair(data); auto pairs = factors.map!(p => tuple(p[0].reduce!min, p[1])); writeln("N. with largest min factor: ", pairs.reduce!max[1]); } //---- It errors in swap because of internal pointers, when calling Tuple.opAssign. You'll notice it now works in Head, but this is only because we lifted the check in: https://github.com/D-Programming-Language/phobos/pull/1390 However, even if the code "runs", it is still wrong, and not yet fixed, as evidenced by this test: //---- struct S { invariant() { assert(checksum == 1234567890); } this(ulong u){n = u;} void opAssign(S s){this.n = s.n;} ulong n; ulong checksum = 1234567890; } void main() { import std.stdio, std.algorithm, std.parallelism, std.typecons; immutable ulong[] data = [ 2UL^^59-1, 2UL^^59-1, 2UL^^59-1, 112_272_537_195_293UL ]; static auto genPair(ulong n) { return S(n); } taskPool.amap!genPair(data); } //----

Commits pushed to master at https://github.com/D-Programming-Language/phobos https://github.com/D-Programming-Language/phobos/commit/bdb68f809432b6a154a52911683c3da85cd0de88 Fix Issue 12733 - parallelism.amap incorrect assignment without initialization https://github.com/D-Programming-Language/phobos/commit/2e3ed8d97ae81c170f1b16bcc4d74b1f560db178 Merge pull request #2161 from monarchdodra/parallelism Fix Issue 12733 - parallelism.amap incorrect assignment without initiali...