fix #7295: use move(result) inside template to avoid copy with --gc:refc (#18168)

lib/pure/collections/sequtils.nim

@@ -1014,27 +1014,27 @@ template applyIt*(varSeq, op: untyped) =
 
 
 template newSeqWith*(len: int, init: untyped): untyped =
-  ## Creates a new sequence of length `len`, calling `init` to initialize
-  ## each value of the sequence.
-  ##
-  ## Useful for creating "2D" sequences - sequences containing other sequences
-  ## or to populate fields of the created sequence.
+  ## Creates a new `seq` of length `len`, calling `init` to initialize
+  ## each value of the seq.
   ##
+  ## Useful for creating "2D" seqs - seqs containing other seqs
+  ## or to populate fields of the created seq.
   runnableExamples:
-    ## Creates a sequence containing 5 bool sequences, each of length of 3.
+    ## Creates a seq containing 5 bool seqs, each of length of 3.
     var seq2D = newSeqWith(5, newSeq[bool](3))
     assert seq2D.len == 5
     assert seq2D[0].len == 3
     assert seq2D[4][2] == false
 
-    ## Creates a sequence of 20 random numbers from 1 to 10
-    import random
-    var seqRand = newSeqWith(20, rand(10))
+    ## Creates a seq with random numbers
+    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:
     result[i] = init
-  result
+  move(result) # refs bug #7295
 
 func mapLitsImpl(constructor: NimNode; op: NimNode; nested: bool;
                  filter = nnkLiterals): NimNode =