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|
discard """
output: "1\n10\n1\n10"
nimout: '''
bar instantiated with 1
bar instantiated with 10
'''
"""
import typetraits
type
Foo = object
proc defaultFoo: Foo = discard
proc defaultInt: int = 1
proc defaultTInt(T: type): int = 2
proc defaultTFoo[T](x: typedesc[T]): Foo = discard
proc defaultTOldSchool[T](x: typedesc[T]): T = discard
proc defaultTModern(T: type): T = discard
proc specializedDefault(T: type int): int = 10
proc specializedDefault(T: type string): string = "default"
converter intFromFoo(x: Foo): int = 3
proc consumeInt(x: int) =
discard
const activeTests = {1..100}
when true:
template test(n, body) =
when n in activeTests:
block:
body
template reject(x) =
static: assert(not compiles(x))
test 1:
proc t[T](val: T = defaultInt()) =
consumeInt val
t[int]()
reject t[string]()
test 2:
proc t1[T](val: T = defaultFoo()) =
static:
assert type(val).name == "int"
assert T.name == "int"
consumeInt val
# here, the converter should kick in, but notice
# how `val` is still typed `int` inside the proc.
t1[int]()
proc t2[T](val: T = defaultFoo()) =
discard
reject t2[string]()
test 3:
proc tInt[T](val = defaultInt()): string =
return type(val).name
doAssert tInt[int]() == "int"
doAssert tInt[string]() == "int"
proc tInt2[T](val = defaultTInt(T)): string =
return type(val).name
doAssert tInt2[int]() == "int"
doAssert tInt2[string]() == "int"
proc tDefTModern[T](val = defaultTModern(T)): string =
return type(val).name
doAssert tDefTModern[int]() == "int"
doAssert tDefTModern[string]() == "string"
doAssert tDefTModern[Foo]() == "Foo"
proc tDefTOld[T](val = defaultTOldSchool(T)): string =
return type(val).name
doAssert tDefTOld[int]() == "int"
doAssert tDefTOld[string]() == "string"
doAssert tDefTOld[Foo]() == "Foo"
test 4:
proc t[T](val: T = defaultTFoo(T)): string =
return type(val).name
doAssert t[int]() == "int"
doAssert t[Foo]() == "Foo"
reject t[string]()
test 5:
proc t1[T](a: T = specializedDefault(T)): T =
return a
doAssert t1[int]() == 10
doAssert t1[string]() == "default"
proc t2[T](a: T, b = specializedDefault(T)): auto =
return $a & $b
doAssert t2(5) == "510"
doAssert t2("string ") == "string default"
proc t3[T](a: T, b = specializedDefault(type(a))): auto =
return $a & $b
doAssert t3(100) == "10010"
doAssert t3("another ") == "another default"
test 6:
# https://github.com/nim-lang/Nim/issues/5595
type
Point[T] = object
x, y: T
proc getOrigin[T](): Point[T] = Point[T](x: 0, y: 0)
proc rotate[T](point: Point[T], radians: float,
origin = getOrigin[T]()): Point[T] =
discard
var p = getOrigin[float]()
var rotated = p.rotate(2.1)
test 7:
proc bar(x: static[int]) =
static: echo "bar instantiated with ", x
echo x
proc foo(x: static[int] = 1) =
bar(x)
foo()
foo(10)
foo(1)
foo(10)
|