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discard """
output: "XXXXX01234"
"""
iterator modPairs(a: var array[0..4,string]): tuple[key: int, val: var string] =
for i in 0..a.high:
yield (key: i, val: a[i])
iterator modItems*[T](a: var array[0..4,T]): var T =
for i in 0..a.high:
yield a[i]
var
arr = ["a", "b", "c", "d", "e"]
for a in modItems(arr):
a = "X"
for a in items(arr):
stdout.write(a)
for i, a in modPairs(arr):
a = $i
for a in items(arr):
stdout.write(a)
echo ""
#--------------------------------------------------------------------
# Lent iterators
#--------------------------------------------------------------------
type
NonCopyable = object
x: int
proc `=destroy`(o: var NonCopyable) =
discard
proc `=copy`(dst: var NonCopyable, src: NonCopyable) {.error.}
proc `=sink`(dst: var NonCopyable, src: NonCopyable) =
dst.x = src.x
iterator lentItems[T](a: openArray[T]): lent T =
for i in 0..a.high:
yield a[i]
iterator lentPairs[T](a: array[0..1, T]): tuple[key: int, val: lent T] =
for i in 0..a.high:
yield (key: i, val: a[i])
let arr1 = [1, 2, 3]
let arr2 = @["a", "b", "c"]
let arr3 = [NonCopyable(x: 1), NonCopyable(x: 2)]
let arr4 = @[(1, "a"), (2, "b"), (3, "c")]
var accum: string
for x in lentItems(arr1):
accum &= $x
doAssert(accum == "123")
accum = ""
for x in lentItems(arr2):
accum &= $x
doAssert(accum == "abc")
accum = ""
for val in lentItems(arr3):
accum &= $val.x
doAssert(accum == "12")
accum = ""
for i, val in lentPairs(arr3):
accum &= $i & "-" & $val.x & " "
doAssert(accum == "0-1 1-2 ")
accum = ""
for i, val in lentItems(arr4):
accum &= $i & "-" & $val & " "
doAssert(accum == "1-a 2-b 3-c ")
accum = ""
for (i, val) in lentItems(arr4):
accum &= $i & "-" & $val & " "
doAssert(accum == "1-a 2-b 3-c ")
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