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// check-pass
#![allow(dead_code, incomplete_features)]
#![feature(generic_const_exprs)]
const fn min(a: usize, b: usize) -> usize {
if a < b {
a
} else {
b
}
}
trait Trait1<Inner1>
where
Self: Sized,
{
fn crash_here()
where
Inner1: Default,
{
Inner1::default();
}
}
struct Struct1<T>(T);
impl<T> Trait1<T> for Struct1<T> {}
trait Trait2<Inner2>
where
Self: Sized,
{
type Assoc: Trait1<Inner2>;
fn call_crash()
where
Inner2: Default,
{
// if Inner2 implements Default, we can call crash_here.
Self::Assoc::crash_here();
}
}
struct Struct2<const SIZE1: usize, const SIZE2: usize> {}
/*
where
[(); min(SIZE1, SIZE2)]:,
{
elem: [i32; min(SIZE1, SIZE2)],
}
*/
impl<const SIZE1: usize, const SIZE2: usize> Trait2<[i32; min(SIZE1, SIZE2)]>
for Struct2<SIZE1, SIZE2>
{
type Assoc = Struct1<[i32; min(SIZE1, SIZE2)]>;
// dose Struct1<[i32; min(SIZE1, SIZE2)]> implement Default?
}
fn main() {
pattern2();
print_fully_name(<Struct2<1, 2> as Trait2<[i32; min(1, 2)]>>::Assoc::crash_here);
// <compiler_bug2::Struct1<[i32; 1]> as compiler_bug2::Trait1<[i32; 1]>>::crash_here
}
fn pattern1() {
// no crash
<Struct2<1, 2> as Trait2<[i32; min(1, 2)]>>::Assoc::crash_here();
<Struct2<1, 2> as Trait2<[i32; min(1, 2)]>>::call_crash();
}
fn pattern2() {
// crash
<Struct2<1, 2> as Trait2<[i32; min(1, 2)]>>::call_crash();
// undefined reference to `compiler_bug2::Trait1::crash_here'
}
fn pattern3() {
// no crash
<Struct2<1, 2> as Trait2<[i32; min(1, 2)]>>::Assoc::crash_here();
}
fn print_fully_name<T>(_: T) {
let _ = std::any::type_name::<T>();
}
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