Destructors: move into nkTupleConstr and move on tuple unpacking (#9776)

tests/destructor/t6434.nim

@@ -1,21 +1,26 @@
 discard """
   exitcode: 0
-  output: '''assingment
-assingment
-assingment
-assingment
-'''
+  output: ""
 """
 
 type
   Foo* = object
     boo: int
 
+var sink_counter = 0
+var assign_counter = 0
+
+proc `=sink`(dest: var Foo, src: Foo) =
+  sink_counter.inc
+
 proc `=`(dest: var Foo, src: Foo) =
-  debugEcho "assingment"
+  assign_counter.inc
 
 proc test(): auto =
   var a,b : Foo
-  return (a, b)
+  return (a, b, Foo(boo: 5))
 
-var (a, b) = test()
+var (a, b, _) = test()
+
+doAssert: assign_counter == 0
+doAssert: sink_counter == 9

tests/destructor/tmove_objconstr.nim

@@ -60,3 +60,62 @@ for x in getPony():
 # XXX this needs to be enabled once top level statements
 # produce destructor calls again.
 #echo "Pony is dying!"
+
+
+#------------------------------------------------------------
+#-- Move into tuple constructor and move on tuple unpacking
+#------------------------------------------------------------
+
+type
+  MySeqNonCopyable* = object
+    len: int 
+    data: ptr UncheckedArray[float]
+
+proc `=destroy`*(m: var MySeqNonCopyable) {.inline.} =
+  if m.data != nil:
+    deallocShared(m.data)
+    m.data = nil
+
+proc `=`*(m: var MySeqNonCopyable, m2: MySeqNonCopyable) {.error.}
+
+proc `=sink`*(m: var MySeqNonCopyable, m2: MySeqNonCopyable) {.inline.} =
+  if m.data != m2.data:
+    if m.data != nil:
+      `=destroy`(m)
+    m.len = m2.len
+    m.data = m2.data
+
+proc len*(m: MySeqNonCopyable): int {.inline.} = m.len
+
+proc `[]`*(m: MySeqNonCopyable; i: int): float {.inline.} =
+  m.data[i.int]
+
+proc `[]=`*(m: var MySeqNonCopyable; i, val: float) {.inline.} =
+  m.data[i.int] = val
+
+proc setTo(s: var MySeqNonCopyable, val: float) = 
+  for i in 0..<s.len.int:
+    s.data[i] = val
+
+proc newMySeq*(size: int, initial_value = 0.0): MySeqNonCopyable =#
+  result.len = size
+  if size > 0:
+    result.data = cast[ptr UncheckedArray[float]](createShared(float, size))
+
+  result.setTo(initial_value)
+
+proc myfunc(x, y: int): (MySeqNonCopyable, MySeqNonCopyable) =
+  result = (newMySeq(x, 1.0), newMySeq(y, 5.0))
+
+proc myfunc2(x, y: int): tuple[a: MySeqNonCopyable, b:int, c:MySeqNonCopyable] =
+  (a: newMySeq(x, 1.0), b:0, c:newMySeq(y, 5.0))
+
+let (seq1, seq2) = myfunc(2, 3)
+doAssert seq1.len == 2
+doAssert seq1[0] == 1.0
+doAssert seq2.len == 3
+doAssert seq2[0] == 5.0
+
+var (seq3, i, _) = myfunc2(2, 3)
+doAssert seq3.len == 2
+doAssert seq3[0] == 1.0