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discard """
output: '''10.0
60.0
90.0
120.0
10.0
60.0
90.0
120.0
8 8'''
cmd: '''nim c --newruntime $file'''
"""
import typetraits
type
opt[T] = object
data: ptr T
var
allocCount, deallocCount: int
proc `=destroy`*[T](x: var opt[T]) =
if x.data != nil:
when not supportsCopyMem(T):
`=destroy`(x.data[])
dealloc(x.data)
inc deallocCount
x.data = nil
proc `=`*[T](a: var opt[T]; b: opt[T]) =
if a.data == b.data: return
if a.data != nil:
dealloc(a.data)
inc deallocCount
a.data = nil
if b.data != nil:
a.data = cast[type(a.data)](alloc(sizeof(T)))
inc allocCount
when supportsCopyMem(T):
copyMem(a.data, b.data, sizeof(T))
else:
a.data[] = b.data[]
proc `=sink`*[T](a: var opt[T]; b: opt[T]) =
if a.data != nil and a.data != b.data:
dealloc(a.data)
inc deallocCount
a.data = b.data
proc createOpt*[T](x: T): opt[T] =
result.data = cast[type(result.data)](alloc(sizeof(T)))
inc allocCount
result.data[] = x
template `[]`[T](x: opt[T]): T =
assert x.p != nil, "attempt to read from moved/destroyed value"
x.p[]
template `?=`[T](it: untyped; x: opt[T]): bool =
template it: untyped {.inject.} = x.data[]
if x.data != nil:
true
else:
false
type
Tree = object
data: float
le, ri: opt[Tree]
proc createTree(data: float): Tree =
result.data = data
proc insert(t: var opt[Tree]; newVal: float) =
#if it ?= t:
if t.data != nil:
if newVal < t.data[].data:
insert(t.data[].le, newVal)
elif t.data[].data < newVal:
insert(t.data[].ri, newVal)
else:
discard "already in the tree"
else:
t = createOpt(Tree(data: newVal))
proc write(t: opt[Tree]) =
if it ?= t:
write(it.le)
write stdout, it.data, "\n"
write(it.ri)
proc use(t: opt[Tree]) = discard
proc main =
var t: opt[Tree]
insert t, 60.0
insert t, 90.0
insert t, 10.0
insert t, 120.0
write t
let copy = t
write copy
use t
main()
echo allocCount, " ", deallocCount
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