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Copy pathtinitchecks_v2.nim
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83 lines (65 loc) · 1.48 KB
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discard """
cmd: "nim check $file"
action: "compile"
"""
{.experimental: "strictDefs".}
proc myopen(f: out File; s: string): bool =
f = default(File)
result = false
proc main =
var f: File
if myopen(f, "aarg"):
f.close
proc invalid =
var s: seq[string]
s.add "abc" #[tt.Warning
^ use explicit initialization of 's' for clarity [Uninit] ]#
proc valid =
var s: seq[string] = @[]
s.add "abc" # valid!
main()
invalid()
valid()
proc branchy(cond: bool) =
var s: seq[string]
if cond:
s = @["y"]
else:
s = @[]
s.add "abc" # valid!
branchy true
proc p(x: out int; y: out string; cond: bool) = #[tt.Warning
^ Cannot prove that 'y' is initialized. This will become a compile time error in the future. [ProveInit] ]#
x = 4
if cond:
y = "abc"
# error: not every path initializes 'y'
var gl: int
var gs: string
p gl, gs, false
proc canRaise(x: int): int =
result = x
raise newException(ValueError, "wrong")
proc currentlyValid(x: out int; y: out string; cond: bool) =
x = canRaise(45)
y = "abc" # <-- error: not every path initializes 'y'
currentlyValid gl, gs, false
block: # previously effects/toutparam
proc gah[T](x: out T) =
x = 3
proc arr1 =
var a: array[2, int]
var x: int
gah(x)
a[0] = 3
a[x] = 3
echo x
arr1()
proc arr2 =
var a: array[2, int]
var x: int
a[0] = 3
a[x] = 3 #[tt.Warning
^ use explicit initialization of 'x' for clarity [Uninit] ]#
echo x
arr2()