More converter fixes (#9737)

* fixes #9735
* fixes #9736
* fixes #3503

tests/converter/tconvert.nim

@@ -26,3 +26,19 @@ block:
   var x = "101"
   var y: int = x # instantiate withVar
   doAssert(y == ord('0'))
+
+
+######################
+# bug #3503
+type Foo = object
+  r: float
+
+converter toFoo(r: float): Foo =
+  result.r = r
+
+proc `+=`*(x: var Foo, r: float) =
+  x.r += r
+
+var a: Foo
+a.r += 3.0
+

tests/converter/tconverter_unique_ptr.nim

@@ -2,9 +2,7 @@
 discard """
   file: "tconverter_unique_ptr.nim"
   targets: "c cpp"
-  output: '''5
-2.0 5
-'''
+  output: ""
 """
 
 ## Bugs 9698 and 9699
@@ -22,6 +20,8 @@ type
     data: ptr UncheckedArray[float]
 
 proc `$`(x: MyLen): string {.borrow.}
+proc `==`(x1, x2: MyLen): bool {.borrow.}
+
 
 proc `=destroy`*(m: var MySeq) {.inline.} =
   if m.data != nil:
@@ -50,10 +50,12 @@ proc len*(m: MySeq): MyLen {.inline.} = m.len
 
 proc lenx*(m: var MySeq): MyLen {.inline.} = m.len
 
-
 proc `[]`*(m: MySeq; i: MyLen): float {.inline.} =
   m.data[i.int]
 
+proc `[]`*(m: var MySeq; i: MyLen): var float {.inline.} =
+  m.data[i.int]
+
 proc `[]=`*(m: var MySeq; i: MyLen, val: float) {.inline.} =
   m.data[i.int] = val
 
@@ -97,11 +99,55 @@ proc newUniquePtr*[T](val: sink T): UniquePtr[T] =
 converter convertPtrToObj*[T](p: UniquePtr[T]): var T =
   result = p.val[]
 
-
 var pu = newUniquePtr(newMySeq(5, 1.0))
-echo pu.len
+let pu2 = newUniquePtr(newMySeq(5, 1.0))
+doAssert: pu.len == 5
+doAssert: pu2.len == 5
+doAssert: pu.lenx == 5
+doAssert: pu2.lenx == 5
 
 pu[0] = 2.0
-echo pu[0], " ", pu.lenx
+pu2[0] = 2.0
+doAssert pu[0] == 2.0
+doAssert: pu2[0] == 2.0
 
+##-----------------------------------------------------------------------------------------
+## Bugs #9735 and #9736 
+type
+  ConstPtr*[T] = object
+    ## This pointer makes it impossible to change underlying value
+    ## as it returns only `lent T`
+    val: ptr T
 
+proc `=destroy`*[T](p: var ConstPtr[T]) =
+  if p.val != nil:
+    `=destroy`(p.val[])
+    dealloc(p.val)
+    p.val = nil
+
+proc `=`*[T](dest: var ConstPtr[T], src: ConstPtr[T]) {.error.}
+
+proc `=sink`*[T](dest: var ConstPtr[T], src: ConstPtr[T]) {.inline.} =
+  if dest.val != nil and dest.val != src.val:
+    `=destroy`(dest)
+  dest.val = src.val
+
+proc newConstPtr*[T](val: sink T): ConstPtr[T] =
+  result.val = cast[type(result.val)](alloc(sizeof(result.val[])))
+  reset(result.val[])
+  result.val[] = val
+
+converter convertConstPtrToObj*[T](p: ConstPtr[T]): lent T =
+  result = p.val[]
+
+var pc = newConstPtr(newMySeq(3, 1.0))
+let pc2 = newConstPtr(newMySeq(3, 1.0))
+doAssert: pc.len == 3
+doAssert: pc.len == 3
+doAssert: compiles(pc.lenx == 2) == false
+doAssert: compiles(pc2.lenx == 2) == false
+doAssert: compiles(pc[0] = 2.0) == false
+doAssert: compiles(pc2[0] = 2.0) == false
+
+doAssert: pc[0] == 1.0
+doAssert: pc2[0] == 1.0