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//@ known-bug: #132960
#![feature(adt_const_params, const_ptr_read, generic_const_exprs, unsized_const_params)]
const fn concat_strs<const A: &'static str, const B: &'static str>() -> &'static str
where
[(); A.len()]:,
[(); B.len()]:,
[(); A.len() + B.len()]:,
{
#[repr(C)]
#[repr(C)]
const fn concat_arr<const M: usize, const N: usize>(a: [u8; M], b: [u8; N]) -> [u8; M + N] {}
struct Inner<const A: &'static str, const B: &'static str>;
impl<const A: &'static str, const B: &'static str> Inner<A, B>
where
[(); A.len()]:,
[(); B.len()]:,
[(); A.len() + B.len()]:,
{
const ABSTR: &'static str = unsafe {
std::str::from_utf8_unchecked(&concat_arr(
A.as_ptr().cast().read(),
B.as_ptr().cast().read(),
))
};
}
Inner::<A, B>::ABSTR
}
const FOO: &str = "foo";
const BAR: &str = "bar";
const FOOBAR: &str = concat_strs::<FOO, BAR>();
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