overloading of '=' works

tests/assign/moverload_asgn2.nim

@@ -0,0 +1,10 @@
+type
+  Concrete* = object
+    a*, b*: string
+    rc*: int # refcount
+
+proc `=`(d: var Concrete; src: Concrete) =
+  shallowCopy(d.a, src.a)
+  shallowCopy(d.b, src.b)
+  dec d.rc
+  d.rc = src.rc + 1

tests/assign/toverload_asgn1.nim

@@ -0,0 +1,75 @@
+discard """
+  output: '''Concrete '='
+Concrete '='
+Concrete '='
+Concrete '='
+Concrete '='
+GenericT[T] '=' int
+GenericT[T] '=' float
+GenericT[T] '=' float
+GenericT[T] '=' float
+GenericT[T] '=' string
+GenericT[T] '=' int8
+GenericT[T] '=' bool
+GenericT[T] '=' bool
+GenericT[T] '=' bool
+GenericT[T] '=' bool'''
+"""
+
+import typetraits
+
+type
+  Concrete = object
+    a, b: string
+
+proc `=`(d: var Concrete; src: Concrete) =
+  shallowCopy(d.a, src.a)
+  shallowCopy(d.b, src.b)
+  echo "Concrete '='"
+
+var x, y: array[0..2, Concrete]
+var cA, cB: Concrete
+
+var cATup, cBTup: tuple[x: int, ha: Concrete]
+
+x = y
+cA = cB
+cATup = cBTup
+
+type
+  GenericT[T] = object
+    a, b: T
+
+proc `=`[T](d: var GenericT[T]; src: GenericT[T]) =
+  shallowCopy(d.a, src.a)
+  shallowCopy(d.b, src.b)
+  echo "GenericT[T] '=' ", type(T).name
+
+var ag: GenericT[int]
+var bg: GenericT[int]
+
+ag = bg
+
+var xg, yg: array[0..2, GenericT[float]]
+var cAg, cBg: GenericT[string]
+
+var cATupg, cBTupg: tuple[x: int, ha: GenericT[int8]]
+
+xg = yg
+cAg = cBg
+cATupg = cBTupg
+
+var caSeqg, cbSeqg: seq[GenericT[bool]]
+newSeq(cbSeqg, 4)
+caSeqg = cbSeqg
+
+when false:
+  type
+    Foo = object
+      case b: bool
+      of false: xx: GenericT[int]
+      of true: yy: bool
+
+  var
+    a, b: Foo
+  a = b

tests/assign/toverload_asgn2.nim

@@ -0,0 +1,22 @@
+discard """
+  output: '''i value 88
+2aa'''
+"""
+
+import moverload_asgn2
+
+proc passAround(i: int): Concrete =
+  echo "i value ", i
+  result = Concrete(a: "aa", b: "bb", rc: 0)
+
+proc main =
+  let
+    i = 88
+    v = passAround(i)
+    z = v.a
+  var
+    x: Concrete
+  x = v
+  echo x.rc, z # 2aa
+
+main()