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use crate::*;
use core::alloc::Layout;
unsafe impl<T> Facet for &[T]
where
T: Facet,
{
const ARCHETYPE: Self = &[];
const SHAPE: &'static Shape = &const {
Shape::builder()
.layout(Layout::new::<&[T]>())
.def(Def::List(
ListDef::builder()
.vtable(
&const {
ListVTable::builder()
.init_in_place_with_capacity(|_, _| Err(()))
.push(|_, _| {
panic!("Cannot push to &[T]");
})
.len(|ptr| unsafe {
let slice = ptr.as_ref::<&[T]>();
slice.len()
})
.get_item_ptr(|ptr, index| unsafe {
let slice = ptr.as_ref::<&[T]>();
let len = slice.len();
if index >= len {
panic!(
"Index out of bounds: the len is {len} but the index is {index}"
);
}
OpaqueConst::new_unchecked(slice.as_ptr().add(index))
})
.build()
},
)
.t(T::SHAPE)
.build(),
))
.vtable(
&const {
let mut builder = ValueVTable::builder()
.type_name(|f, opts| {
if let Some(opts) = opts.for_children() {
write!(f, "&[")?;
(T::SHAPE.vtable.type_name)(f, opts)?;
write!(f, "]")
} else {
write!(f, "&[⋯]")
}
})
.marker_traits(T::SHAPE.vtable.marker_traits)
.default_in_place(|ptr| unsafe { ptr.write(&[] as &[T]) })
.clone_into(|src, dst| unsafe {
// This works because we're cloning a shared reference (&[T]), not the actual slice data.
// We're just copying the fat pointer (ptr + length) that makes up the slice reference.
dst.write(src.as_ref::<&[T]>())
});
if T::SHAPE.vtable.debug.is_some() {
builder = builder.debug(|value, f| {
let value = unsafe { value.as_ref::<&[T]>() };
write!(f, "[")?;
for (i, item) in value.iter().enumerate() {
if i > 0 {
write!(f, ", ")?;
}
unsafe {
(T::SHAPE.vtable.debug.unwrap_unchecked())(
OpaqueConst::from_ref(item),
f,
)?;
}
}
write!(f, "]")
});
}
if T::SHAPE.vtable.eq.is_some() {
builder = builder.eq(|a, b| {
let a = unsafe { a.as_ref::<&[T]>() };
let b = unsafe { b.as_ref::<&[T]>() };
if a.len() != b.len() {
return false;
}
for (x, y) in a.iter().zip(b.iter()) {
if !unsafe {
(T::SHAPE.vtable.eq.unwrap_unchecked())(
OpaqueConst::from_ref(x),
OpaqueConst::from_ref(y),
)
} {
return false;
}
}
true
});
}
if T::SHAPE.vtable.ord.is_some() {
builder = builder.ord(|a, b| {
let a = unsafe { a.as_ref::<&[T]>() };
let b = unsafe { b.as_ref::<&[T]>() };
for (x, y) in a.iter().zip(b.iter()) {
let ord = unsafe {
(T::SHAPE.vtable.ord.unwrap_unchecked())(
OpaqueConst::from_ref(x),
OpaqueConst::from_ref(y),
)
};
if ord != core::cmp::Ordering::Equal {
return ord;
}
}
a.len().cmp(&b.len())
});
}
if T::SHAPE.vtable.partial_ord.is_some() {
builder = builder.partial_ord(|a, b| {
let a = unsafe { a.as_ref::<&[T]>() };
let b = unsafe { b.as_ref::<&[T]>() };
for (x, y) in a.iter().zip(b.iter()) {
let ord = unsafe {
(T::SHAPE.vtable.partial_ord.unwrap_unchecked())(
OpaqueConst::from_ref(x),
OpaqueConst::from_ref(y),
)
};
match ord {
Some(core::cmp::Ordering::Equal) => continue,
Some(order) => return Some(order),
None => return None,
}
}
a.len().partial_cmp(&b.len())
});
}
if T::SHAPE.vtable.hash.is_some() {
builder = builder.hash(|value, state, hasher| {
let value = unsafe { value.as_ref::<&[T]>() };
for item in value.iter() {
unsafe {
(T::SHAPE.vtable.hash.unwrap_unchecked())(
OpaqueConst::from_ref(item),
state,
hasher,
)
};
}
});
}
builder.build()
},
)
.build()
};
}