75 lines
1.1 KiB
V
75 lines
1.1 KiB
V
interface Animal {
|
|
mut:
|
|
breed string
|
|
}
|
|
|
|
struct Cat {
|
|
padding int // ensures that the field offsets can be different
|
|
mut:
|
|
breed string
|
|
}
|
|
|
|
struct Dog {
|
|
padding [256]u8
|
|
padding2 int
|
|
mut:
|
|
breed string
|
|
}
|
|
|
|
fn use_interface(a Animal) {
|
|
assert a.breed in ['Persian', 'Labrador']
|
|
if a is Cat {
|
|
assert a.breed == 'Persian'
|
|
} else {
|
|
assert a.breed == 'Labrador'
|
|
}
|
|
}
|
|
|
|
fn mutate_interface(mut a Animal) {
|
|
if a is Cat {
|
|
a.breed = 'Siamese'
|
|
} else {
|
|
a.breed = 'Golden Retriever'
|
|
}
|
|
if a is Cat {
|
|
assert a.breed == 'Siamese'
|
|
} else {
|
|
assert a.breed == 'Golden Retriever'
|
|
}
|
|
a.breed = 'what??'
|
|
assert a.breed == 'what??'
|
|
}
|
|
|
|
fn test_interface_fields() {
|
|
mut c := Cat{
|
|
breed: 'Persian'
|
|
}
|
|
mut d := Dog{
|
|
breed: 'Labrador'
|
|
}
|
|
use_interface(c)
|
|
use_interface(d)
|
|
mutate_interface(mut c)
|
|
mutate_interface(mut d)
|
|
assert c.breed == 'what??'
|
|
assert d.breed == 'what??'
|
|
}
|
|
|
|
struct Nofun {
|
|
foo fn (int) int
|
|
}
|
|
|
|
interface NofunInterface {
|
|
foo fn (int) int
|
|
}
|
|
|
|
fn my_fn(a int) int {
|
|
assert a == 123
|
|
return a * 2
|
|
}
|
|
|
|
fn test_interface_fn_pointer_fields() {
|
|
nf := NofunInterface(Nofun{my_fn})
|
|
assert nf.foo(123) == 246
|
|
}
|