1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
|
//@ compile-flags: -Zmir-opt-level=3
//@ run-pass
// Tests that specialization does not cause optimizations running on polymorphic MIR to resolve
// to a `default` implementation.
#![feature(specialization)] //~ WARN the feature `specialization` is incomplete
trait Marker {}
trait SpecializedTrait {
const CONST_BOOL: bool;
const CONST_STR: &'static str;
fn method() -> &'static str;
}
impl <T> SpecializedTrait for T {
default const CONST_BOOL: bool = false;
default const CONST_STR: &'static str = "in default impl";
#[inline(always)]
default fn method() -> &'static str {
"in default impl"
}
}
impl <T: Marker> SpecializedTrait for T {
const CONST_BOOL: bool = true;
const CONST_STR: &'static str = "in specialized impl";
fn method() -> &'static str {
"in specialized impl"
}
}
fn const_bool<T>() -> &'static str {
if <T as SpecializedTrait>::CONST_BOOL {
"in specialized impl"
} else {
"in default impl"
}
}
fn const_str<T>() -> &'static str {
<T as SpecializedTrait>::CONST_STR
}
fn run_method<T>() -> &'static str {
<T as SpecializedTrait>::method()
}
struct TypeA;
impl Marker for TypeA {}
struct TypeB;
#[inline(never)]
fn exit_if_not_eq(left: &str, right: &str) {
if left != right {
std::process::exit(1);
}
}
pub fn main() {
exit_if_not_eq("in specialized impl", const_bool::<TypeA>());
exit_if_not_eq("in default impl", const_bool::<TypeB>());
exit_if_not_eq("in specialized impl", const_str::<TypeA>());
exit_if_not_eq("in default impl", const_str::<TypeB>());
exit_if_not_eq("in specialized impl", run_method::<TypeA>());
exit_if_not_eq("in default impl", run_method::<TypeB>());
}
|
