1 files changed, 35 insertions, 5 deletions
diff --git a/lib/pure/collections/sequtils.nim b/lib/pure/collections/sequtils.nim
index 1773e827b..3c0d8dc0e 100644
--- a/lib/pure/collections/sequtils.nim
+++ b/lib/pure/collections/sequtils.nim
@@ -82,7 +82,8 @@ runnableExamples:
 
 import std/private/since
 
-import macros
+import std/macros
+from std/typetraits import supportsCopyMem
 
 when defined(nimPreviewSlimSystem):
   import std/assertions
@@ -140,6 +141,22 @@ func concat*[T](seqs: varargs[seq[T]]): seq[T] =
       result[i] = itm
       inc(i)
 
+func addUnique*[T](s: var seq[T], x: sink T) =
+  ## Adds `x` to the container `s` if it is not already present. 
+  ## Uses `==` to check if the item is already present.
+  runnableExamples:
+    var a = @[1, 2, 3]
+    a.addUnique(4)
+    a.addUnique(4)
+    assert a == @[1, 2, 3, 4]
+
+  for i in 0..high(s):
+    if s[i] == x: return
+  when declared(ensureMove):
+    s.add ensureMove(x)
+  else:
+    s.add x
+
 func count*[T](s: openArray[T], x: T): int =
   ## Returns the number of occurrences of the item `x` in the container `s`.
   ##
@@ -248,6 +265,15 @@ func maxIndex*[T](s: openArray[T]): int {.since: (1, 1).} =
   for i in 1..high(s):
     if s[i] > s[result]: result = i
 
+func minmax*[T](x: openArray[T]): (T, T) =
+  ## The minimum and maximum values of `x`. `T` needs to have a `<` operator.
+  var l = x[0]
+  var h = x[0]
+  for i in 1..high(x):
+    if x[i] < l: l = x[i]
+    if h < x[i]: h = x[i]
+  result = (l, h)
+
 
 template zipImpl(s1, s2, retType: untyped): untyped =
   proc zip*[S, T](s1: openArray[S], s2: openArray[T]): retType =
@@ -851,7 +877,7 @@ template toSeq*(iter: untyped): untyped =
           inc i
         result
     else:
-      var result: seq[typeof(iter)]# = @[]
+      var result: seq[typeof(iter)] = @[]
       for x in iter:
         result.add(x)
       result
@@ -1077,9 +1103,13 @@ template newSeqWith*(len: int, init: untyped): untyped =
     import std/random
     var seqRand = newSeqWith(20, rand(1.0))
     assert seqRand[0] != seqRand[1]
-
-  var result = newSeq[typeof(init)](len)
-  for i in 0 ..< len:
+  type T = typeof(init)
+  let newLen = len
+  when supportsCopyMem(T) and declared(newSeqUninit):
+    var result = newSeqUninit[T](newLen)
+  else: # TODO: use `newSeqUnsafe` when that's available
+    var result = newSeq[T](newLen)
+  for i in 0 ..< newLen:
     result[i] = init
   move(result) # refs bug #7295