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Add many more number conversions
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This allows us to write checked conversions from other integer types, including usize.
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@ObsidianMinor
ObsidianMinor committed Oct 4, 2024
1 parent 90821e3 commit 8906cc3
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Showing 2 changed files with 53 additions and 27 deletions.
60 changes: 43 additions & 17 deletions recapn/src/num.rs
View file
Original file line number Diff line number Diff line change
Expand Up @@ -5,6 +5,17 @@ use core::fmt;
use core::hint::unreachable_unchecked;
use core::num::NonZeroU32;

#[derive(Debug, Copy, Clone, PartialEq, Eq)]
pub struct TryFromIntError(pub(crate) ());

impl fmt::Display for TryFromIntError {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
f.write_str("out of range integral type conversion attempted")
}
}

impl core::error::Error for TryFromIntError {}

/// A simple macro to implement cmp traits using the inner type gotten through a get() function
macro_rules! get_cmp {
($ty1:ty, $ty2:ty) => {
Expand Down Expand Up @@ -42,6 +53,33 @@ macro_rules! fwd_fmt_traits {
};
}

macro_rules! from_int_impl {
($dst:ty: $in:ty => $($src:ty),*) => {$(
impl From<$src> for $dst {
#[inline]
fn from(value: $src) -> $dst {
let inner = <$in as From<$src>>::from(value);
<$dst>::new_unwrap(inner)
}
}
)*};
}

macro_rules! try_from_int_impl {
($dst:ty: $in:ty => $($src:ty),*) => {$(
impl TryFrom<$src> for $dst {
type Error = TryFromIntError;

#[inline]
fn try_from(value: $src) -> Result<$dst, TryFromIntError> {
let inner = <$in as TryFrom<$src>>::try_from(value)
.map_err(|_| TryFromIntError(()))?;
<$dst>::new(inner).ok_or(TryFromIntError(()))
}
}
)*};
}

/// A 29 bit integer. It cannot be zero.
#[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord)]
pub struct NonZeroU29(NonZeroU32);
Expand Down Expand Up @@ -176,18 +214,15 @@ impl From<Option<NonZeroU29>> for u29 {
}
}

impl From<u16> for u29 {
fn from(v: u16) -> Self {
Self(u32::from(v))
}
}

impl From<u29> for i30 {
fn from(u29(v): u29) -> Self {
Self(v as i32)
}
}

from_int_impl!(u29: u32 => u8, u16);
try_from_int_impl!(u29: u32 => i8, i16, u32, i32, u64, i64, u128, i128, usize, isize);

get_cmp!(NonZeroU29, u29);
get_cmp!(u29, NonZeroU29);

Expand Down Expand Up @@ -242,14 +277,5 @@ impl i30 {

fwd_fmt_traits!(i30);

impl From<u16> for i30 {
fn from(v: u16) -> Self {
Self(i32::from(v))
}
}

impl From<i16> for i30 {
fn from(v: i16) -> Self {
Self(i32::from(v))
}
}
from_int_impl!(i30: i32 => u8, i8, u16, i16);
try_from_int_impl!(i30: i32 => u32, i32, u64, i64, u128, i128, usize, isize);
20 changes: 10 additions & 10 deletions recapn/src/ptr.rs
View file
Original file line number Diff line number Diff line change
Expand Up @@ -1720,7 +1720,7 @@ impl<'a> ObjectReader<'a> {
// The landing pad is another far pointer. The next pointer is a tag describing our
// pointed-to object
// SAFETY: We know from the above that this landing pad is two words, so this is safe
let tag = unsafe { *pad.offset(1.into()).as_ref_unchecked().as_wire_ptr() };
let tag = unsafe { *pad.offset(1u8.into()).as_ref_unchecked().as_wire_ptr() };

let far_ptr = pad_ptr.try_far_ptr()?;
Ok(Content {
Expand Down Expand Up @@ -1838,7 +1838,7 @@ impl<'a> ObjectReader<'a> {
.ok_or(Error::UnsupportedInlineCompositeElementTag)?;

// move past the tag pointer to get the start of the list
let first = unsafe { tag_ptr.offset(1.into()).as_ref_unchecked() };
let first = unsafe { tag_ptr.offset(1u8.into()).as_ref_unchecked() };

let element_count = tag.inline_composite_element_count();

Expand Down Expand Up @@ -3226,7 +3226,7 @@ impl<'a> ObjectBuilder<'a> {
.expect("far pointer cannot point to a read-only segment");

let content = if double_far {
let tag = unsafe { ptr.offset(1.into()).as_ref_unchecked() };
let tag = unsafe { ptr.offset(1u8.into()).as_ref_unchecked() };
let far_ptr = ptr
.as_wire_ptr()
.try_far_ptr()
Expand Down Expand Up @@ -3269,7 +3269,7 @@ impl<'a> ObjectBuilder<'a> {

builder.set_ptr(pad_ptr, WirePtr::NULL);
if far.double_far() {
let content_ptr = unsafe { pad_ptr.offset(1.into()).as_ref_unchecked() };
let content_ptr = unsafe { pad_ptr.offset(1u8.into()).as_ref_unchecked() };
builder.set_ptr(content_ptr, WirePtr::NULL);
}
}
Expand Down Expand Up @@ -3476,7 +3476,7 @@ impl<'a> ObjectBuilder<'a> {
);
// since the list has no size, any pointer is valid here, even one beyond the end of the segment
return Ok((
unsafe { ptr.offset(1.into()).as_ref_unchecked() },
unsafe { ptr.offset(1u8.into()).as_ref_unchecked() },
ObjectLen::ZERO,
self.clone(),
));
Expand Down Expand Up @@ -3637,7 +3637,7 @@ impl<'a> ObjectBuilder<'a> {
.struct_ptr()
.expect("inline composite list with non-struct elements is not supported");

let list_start = unsafe { start.offset(1.into()).as_ref_unchecked() };
let list_start = unsafe { start.offset(1u8.into()).as_ref_unchecked() };
let size = tag.size();

ListContent {
Expand Down Expand Up @@ -5036,7 +5036,7 @@ impl<'a, T: Table> ListBuilder<'a, T> {
builder,
ptr,
table,
element_count: 0.into(),
element_count: ElementCount::ZERO,
element_size,
}
}
Expand Down Expand Up @@ -6697,7 +6697,7 @@ mod tests {
let mut list = builder
.ptr_field_mut(1)
.unwrap()
.init_list(ElementSize::FourBytes, 3.into());
.init_list(ElementSize::FourBytes, 3u8.into());
assert_eq!(list.len().get(), 3);
unsafe {
list.set_data_unchecked::<i32>(0, 200);
Expand All @@ -6709,7 +6709,7 @@ mod tests {
{
let mut list = builder.ptr_field_mut(2).unwrap().init_list(
ElementSize::InlineComposite(StructSize { data: 1, ptrs: 1 }),
4.into(),
4u8.into(),
);
assert_eq!(list.len().get(), 4);
for i in 0..4 {
Expand All @@ -6727,7 +6727,7 @@ mod tests {
let mut list = builder
.ptr_field_mut(3)
.unwrap()
.init_list(ElementSize::Pointer, 5.into());
.init_list(ElementSize::Pointer, 5u8.into());
assert_eq!(list.len().get(), 5);
for i in 0..5 {
let mut element = unsafe {
Expand Down

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