use sink and lent in deques (#17661)

* use sink and lent in deques

* Update lib/pure/collections/deques.nim

Co-authored-by: Andreas Rumpf <rumpf_a@web.de>

Co-authored-by: Andreas Rumpf <rumpf_a@web.de>

2 files changed, 61 insertions, 12 deletions

diff --git a/lib/pure/collections/deques.nim b/lib/pure/collections/deques.nim
index c8bbb1cc6..d2d53d993 100644
--- a/lib/pure/collections/deques.nim
+++ b/lib/pure/collections/deques.nim
@@ -50,7 +50,7 @@ runnableExamples:
 
 import std/private/since
 
-import math
+import std/math
 
 type
   Deque*[T] = object
@@ -120,7 +120,7 @@ template xBoundsCheck(deq, i) =
       raise newException(IndexDefect,
                          "Out of bounds: " & $i & " < 0")
 
-proc `[]`*[T](deq: Deque[T], i: Natural): T {.inline.} =
+proc `[]`*[T](deq: Deque[T], i: Natural): lent T {.inline.} =
   ## Accesses the `i`-th element of `deq`.
   runnableExamples:
     let a = [10, 20, 30, 40, 50].toDeque
@@ -142,7 +142,7 @@ proc `[]`*[T](deq: var Deque[T], i: Natural): var T {.inline.} =
   xBoundsCheck(deq, i)
   return deq.data[(deq.head + i) and deq.mask]
 
-proc `[]=`*[T](deq: var Deque[T], i: Natural, val: T) {.inline.} =
+proc `[]=`*[T](deq: var Deque[T], i: Natural, val: sink T) {.inline.} =
   ## Sets the `i`-th element of `deq` to `val`.
   runnableExamples:
     var a = [10, 20, 30, 40, 50].toDeque
@@ -154,7 +154,7 @@ proc `[]=`*[T](deq: var Deque[T], i: Natural, val: T) {.inline.} =
   xBoundsCheck(deq, i)
   deq.data[(deq.head + i) and deq.mask] = val
 
-proc `[]`*[T](deq: Deque[T], i: BackwardsIndex): T {.inline.} =
+proc `[]`*[T](deq: Deque[T], i: BackwardsIndex): lent T {.inline.} =
   ## Accesses the backwards indexed `i`-th element.
   ##
   ## `deq[^1]` is the last element.
@@ -180,7 +180,7 @@ proc `[]`*[T](deq: var Deque[T], i: BackwardsIndex): var T {.inline.} =
   xBoundsCheck(deq, deq.len - int(i))
   return deq[deq.len - int(i)]
 
-proc `[]=`*[T](deq: var Deque[T], i: BackwardsIndex, x: T) {.inline.} =
+proc `[]=`*[T](deq: var Deque[T], i: BackwardsIndex, x: sink T) {.inline.} =
   ## Sets the backwards indexed `i`-th element of `deq` to `x`.
   ##
   ## `deq[^1]` is the last element.
@@ -194,7 +194,7 @@ proc `[]=`*[T](deq: var Deque[T], i: BackwardsIndex, x: T) {.inline.} =
   xBoundsCheck(deq, deq.len - int(i))
   deq[deq.len - int(i)] = x
 
-iterator items*[T](deq: Deque[T]): T =
+iterator items*[T](deq: Deque[T]): lent T =
   ## Yields every element of `deq`.
   ##
   ## **See also:**
@@ -270,7 +270,7 @@ proc expandIfNeeded[T](deq: var Deque[T]) =
     deq.tail = deq.count
     deq.head = 0
 
-proc addFirst*[T](deq: var Deque[T], item: T) =
+proc addFirst*[T](deq: var Deque[T], item: sink T) =
   ## Adds an `item` to the beginning of `deq`.
   ##
   ## **See also:**
@@ -286,7 +286,7 @@ proc addFirst*[T](deq: var Deque[T], item: T) =
   deq.head = (deq.head - 1) and deq.mask
   deq.data[deq.head] = item
 
-proc addLast*[T](deq: var Deque[T], item: T) =
+proc addLast*[T](deq: var Deque[T], item: sink T) =
   ## Adds an `item` to the end of `deq`.
   ##
   ## **See also:**
@@ -302,7 +302,7 @@ proc addLast*[T](deq: var Deque[T], item: T) =
   deq.data[deq.tail] = item
   deq.tail = (deq.tail + 1) and deq.mask
 
-proc peekFirst*[T](deq: Deque[T]): T {.inline.} =
+proc peekFirst*[T](deq: Deque[T]): lent T {.inline.} =
   ## Returns the first element of `deq`, but does not remove it from the deque.
   ##
   ## **See also:**
@@ -317,7 +317,7 @@ proc peekFirst*[T](deq: Deque[T]): T {.inline.} =
   emptyCheck(deq)
   result = deq.data[deq.head]
 
-proc peekLast*[T](deq: Deque[T]): T {.inline.} =
+proc peekLast*[T](deq: Deque[T]): lent T {.inline.} =
   ## Returns the last element of `deq`, but does not remove it from the deque.
   ##
   ## **See also:**
diff --git a/tests/stdlib/tdeques.nim b/tests/stdlib/tdeques.nim
index 99208d4cf..03e951fce 100644
--- a/tests/stdlib/tdeques.nim
+++ b/tests/stdlib/tdeques.nim
@@ -1,8 +1,11 @@
 discard """
-  targets: "c js"
+  matrix: "--gc:refc; --gc:orc"
+  targets: "c cpp js"
 """
 
 import std/deques
+from std/sequtils import toSeq
+
 
 block:
   proc index(self: Deque[int], idx: Natural): int =
@@ -125,7 +128,7 @@ block:
   foo(1, 5)
   foo(3, 2)
 
-import sets
+import std/sets
 
 block t13310:
   proc main() =
@@ -137,3 +140,49 @@ block t13310:
 
   static:
     main()
+
+
+proc main() =
+  block:
+    let a = [10, 20, 30].toDeque
+    doAssert toSeq(a.pairs) == @[(0, 10), (1, 20), (2, 30)]
+
+  block:
+    let q = [7, 9].toDeque
+    doAssert 7 in q
+    doAssert q.contains(7)
+    doAssert 8 notin q
+
+  block:
+    let a = [10, 20, 30, 40, 50].toDeque
+    doAssert $a == "[10, 20, 30, 40, 50]"
+    doAssert a.peekFirst == 10
+    doAssert len(a) == 5
+
+  block:
+    let a = [10, 20, 30, 40, 50].toDeque
+    doAssert $a == "[10, 20, 30, 40, 50]"
+    doAssert a.peekLast == 50
+    doAssert len(a) == 5
+
+  block:
+    var a = [10, 20, 30, 40, 50].toDeque
+    doAssert $a == "[10, 20, 30, 40, 50]"
+    doAssert a.popFirst == 10
+    doAssert $a == "[20, 30, 40, 50]"
+
+  block:
+    var a = [10, 20, 30, 40, 50].toDeque
+    doAssert $a == "[10, 20, 30, 40, 50]"
+    doAssert a.popLast == 50
+    doAssert $a == "[10, 20, 30, 40]"
+
+  block:
+    var a = [10, 20, 30, 40, 50].toDeque
+    doAssert $a == "[10, 20, 30, 40, 50]"
+    clear(a)
+    doAssert len(a) == 0
+
+
+static: main()
+main()