}
}
-/// Creates a struct type `S` that can be used as an index with
-/// `IndexVec` and so on.
-///
-/// There are two ways of interacting with these indices:
-///
-/// - The `From` impls are the preferred way. So you can do
-/// `S::from(v)` with a `usize` or `u32`. And you can convert back
-/// to an integer with `u32::from(s)`.
-///
-/// - Alternatively, you can use the methods `S::new(v)` and `s.index()`
-/// to create/return a value.
-///
-/// Internally, the index uses a u32, so the index must not exceed
-/// `u32::MAX`. You can also customize things like the `Debug` impl,
-/// what traits are derived, and so forth via the macro.
-#[macro_export]
-#[allow_internal_unstable(step_trait, rustc_attrs, trusted_step)]
-macro_rules! newtype_index {
- // ---- public rules ----
-
- // Use default constants
- ($(#[$attrs:meta])* $v:vis struct $name:ident { .. }) => (
- $crate::newtype_index!(
- // Leave out derives marker so we can use its absence to ensure it comes first
- @attrs [$(#[$attrs])*]
- @type [$name]
- // shave off 256 indices at the end to allow space for packing these indices into enums
- @max [0xFFFF_FF00]
- @vis [$v]
- @debug_format ["{}"]);
- );
-
- // Define any constants
- ($(#[$attrs:meta])* $v:vis struct $name:ident { $($tokens:tt)+ }) => (
- $crate::newtype_index!(
- // Leave out derives marker so we can use its absence to ensure it comes first
- @attrs [$(#[$attrs])*]
- @type [$name]
- // shave off 256 indices at the end to allow space for packing these indices into enums
- @max [0xFFFF_FF00]
- @vis [$v]
- @debug_format ["{}"]
- $($tokens)+);
- );
-
- // ---- private rules ----
-
- // Base case, user-defined constants (if any) have already been defined
- (@derives [$($derives:ident,)*]
- @attrs [$(#[$attrs:meta])*]
- @type [$type:ident]
- @max [$max:expr]
- @vis [$v:vis]
- @debug_format [$debug_format:tt]) => (
- $(#[$attrs])*
- #[derive(Copy, PartialEq, Eq, Hash, PartialOrd, Ord, $($derives),*)]
- #[rustc_layout_scalar_valid_range_end($max)]
- $v struct $type {
- private: u32
- }
-
- impl Clone for $type {
- #[inline]
- fn clone(&self) -> Self {
- *self
- }
- }
-
- impl $type {
- /// Maximum value the index can take, as a `u32`.
- $v const MAX_AS_U32: u32 = $max;
-
- /// Maximum value the index can take.
- $v const MAX: Self = Self::from_u32($max);
-
- /// Creates a new index from a given `usize`.
- ///
- /// # Panics
- ///
- /// Will panic if `value` exceeds `MAX`.
- #[inline]
- $v const fn from_usize(value: usize) -> Self {
- assert!(value <= ($max as usize));
- // SAFETY: We just checked that `value <= max`.
- unsafe {
- Self::from_u32_unchecked(value as u32)
- }
- }
-
- /// Creates a new index from a given `u32`.
- ///
- /// # Panics
- ///
- /// Will panic if `value` exceeds `MAX`.
- #[inline]
- $v const fn from_u32(value: u32) -> Self {
- assert!(value <= $max);
- // SAFETY: We just checked that `value <= max`.
- unsafe {
- Self::from_u32_unchecked(value)
- }
- }
-
- /// Creates a new index from a given `u32`.
- ///
- /// # Safety
- ///
- /// The provided value must be less than or equal to the maximum value for the newtype.
- /// Providing a value outside this range is undefined due to layout restrictions.
- ///
- /// Prefer using `from_u32`.
- #[inline]
- $v const unsafe fn from_u32_unchecked(value: u32) -> Self {
- Self { private: value }
- }
-
- /// Extracts the value of this index as a `usize`.
- #[inline]
- $v const fn index(self) -> usize {
- self.as_usize()
- }
-
- /// Extracts the value of this index as a `u32`.
- #[inline]
- $v const fn as_u32(self) -> u32 {
- self.private
- }
-
- /// Extracts the value of this index as a `usize`.
- #[inline]
- $v const fn as_usize(self) -> usize {
- self.as_u32() as usize
- }
- }
-
- impl std::ops::Add<usize> for $type {
- type Output = Self;
-
- fn add(self, other: usize) -> Self {
- Self::from_usize(self.index() + other)
- }
- }
-
- impl $crate::vec::Idx for $type {
- #[inline]
- fn new(value: usize) -> Self {
- Self::from_usize(value)
- }
-
- #[inline]
- fn index(self) -> usize {
- self.as_usize()
- }
- }
-
- impl ::std::iter::Step for $type {
- #[inline]
- fn steps_between(start: &Self, end: &Self) -> Option<usize> {
- <usize as ::std::iter::Step>::steps_between(
- &Self::index(*start),
- &Self::index(*end),
- )
- }
-
- #[inline]
- fn forward_checked(start: Self, u: usize) -> Option<Self> {
- Self::index(start).checked_add(u).map(Self::from_usize)
- }
-
- #[inline]
- fn backward_checked(start: Self, u: usize) -> Option<Self> {
- Self::index(start).checked_sub(u).map(Self::from_usize)
- }
- }
-
- // Safety: The implementation of `Step` upholds all invariants.
- unsafe impl ::std::iter::TrustedStep for $type {}
-
- impl From<$type> for u32 {
- #[inline]
- fn from(v: $type) -> u32 {
- v.as_u32()
- }
- }
-
- impl From<$type> for usize {
- #[inline]
- fn from(v: $type) -> usize {
- v.as_usize()
- }
- }
-
- impl From<usize> for $type {
- #[inline]
- fn from(value: usize) -> Self {
- Self::from_usize(value)
- }
- }
-
- impl From<u32> for $type {
- #[inline]
- fn from(value: u32) -> Self {
- Self::from_u32(value)
- }
- }
-
- $crate::newtype_index!(
- @handle_debug
- @derives [$($derives,)*]
- @type [$type]
- @debug_format [$debug_format]);
- );
-
- // base case for handle_debug where format is custom. No Debug implementation is emitted.
- (@handle_debug
- @derives [$($_derives:ident,)*]
- @type [$type:ident]
- @debug_format [custom]) => ();
-
- // base case for handle_debug, no debug overrides found, so use default
- (@handle_debug
- @derives []
- @type [$type:ident]
- @debug_format [$debug_format:tt]) => (
- impl ::std::fmt::Debug for $type {
- fn fmt(&self, fmt: &mut ::std::fmt::Formatter<'_>) -> ::std::fmt::Result {
- write!(fmt, $debug_format, self.as_u32())
- }
- }
- );
-
- // Debug is requested for derive, don't generate any Debug implementation.
- (@handle_debug
- @derives [Debug, $($derives:ident,)*]
- @type [$type:ident]
- @debug_format [$debug_format:tt]) => ();
-
- // It's not Debug, so just pop it off the front of the derives stack and check the rest.
- (@handle_debug
- @derives [$_derive:ident, $($derives:ident,)*]
- @type [$type:ident]
- @debug_format [$debug_format:tt]) => (
- $crate::newtype_index!(
- @handle_debug
- @derives [$($derives,)*]
- @type [$type]
- @debug_format [$debug_format]);
- );
-
- // Append comma to end of derives list if it's missing
- (@attrs [$(#[$attrs:meta])*]
- @type [$type:ident]
- @max [$max:expr]
- @vis [$v:vis]
- @debug_format [$debug_format:tt]
- derive [$($derives:ident),*]
- $($tokens:tt)*) => (
- $crate::newtype_index!(
- @attrs [$(#[$attrs])*]
- @type [$type]
- @max [$max]
- @vis [$v]
- @debug_format [$debug_format]
- derive [$($derives,)*]
- $($tokens)*);
- );
-
- // By not including the @derives marker in this list nor in the default args, we can force it
- // to come first if it exists. When encodable is custom, just use the derives list as-is.
- (@attrs [$(#[$attrs:meta])*]
- @type [$type:ident]
- @max [$max:expr]
- @vis [$v:vis]
- @debug_format [$debug_format:tt]
- derive [$($derives:ident,)+]
- ENCODABLE = custom
- $($tokens:tt)*) => (
- $crate::newtype_index!(
- @attrs [$(#[$attrs])*]
- @derives [$($derives,)+]
- @type [$type]
- @max [$max]
- @vis [$v]
- @debug_format [$debug_format]
- $($tokens)*);
- );
-
- // By not including the @derives marker in this list nor in the default args, we can force it
- // to come first if it exists. When encodable isn't custom, add serialization traits by default.
- (@attrs [$(#[$attrs:meta])*]
- @type [$type:ident]
- @max [$max:expr]
- @vis [$v:vis]
- @debug_format [$debug_format:tt]
- derive [$($derives:ident,)+]
- $($tokens:tt)*) => (
- $crate::newtype_index!(
- @derives [$($derives,)+]
- @attrs [$(#[$attrs])*]
- @type [$type]
- @max [$max]
- @vis [$v]
- @debug_format [$debug_format]
- $($tokens)*);
- $crate::newtype_index!(@serializable $type);
- );
-
- // The case where no derives are added, but encodable is overridden. Don't
- // derive serialization traits
- (@attrs [$(#[$attrs:meta])*]
- @type [$type:ident]
- @max [$max:expr]
- @vis [$v:vis]
- @debug_format [$debug_format:tt]
- ENCODABLE = custom
- $($tokens:tt)*) => (
- $crate::newtype_index!(
- @derives []
- @attrs [$(#[$attrs])*]
- @type [$type]
- @max [$max]
- @vis [$v]
- @debug_format [$debug_format]
- $($tokens)*);
- );
-
- // The case where no derives are added, add serialization derives by default
- (@attrs [$(#[$attrs:meta])*]
- @type [$type:ident]
- @max [$max:expr]
- @vis [$v:vis]
- @debug_format [$debug_format:tt]
- $($tokens:tt)*) => (
- $crate::newtype_index!(
- @derives []
- @attrs [$(#[$attrs])*]
- @type [$type]
- @max [$max]
- @vis [$v]
- @debug_format [$debug_format]
- $($tokens)*);
- $crate::newtype_index!(@serializable $type);
- );
-
- (@serializable $type:ident) => (
- impl<D: ::rustc_serialize::Decoder> ::rustc_serialize::Decodable<D> for $type {
- fn decode(d: &mut D) -> Self {
- Self::from_u32(d.read_u32())
- }
- }
- impl<E: ::rustc_serialize::Encoder> ::rustc_serialize::Encodable<E> for $type {
- fn encode(&self, e: &mut E) -> Result<(), E::Error> {
- e.emit_u32(self.private)
- }
- }
- );
-
- // Rewrite final without comma to one that includes comma
- (@derives [$($derives:ident,)*]
- @attrs [$(#[$attrs:meta])*]
- @type [$type:ident]
- @max [$max:expr]
- @vis [$v:vis]
- @debug_format [$debug_format:tt]
- $name:ident = $constant:expr) => (
- $crate::newtype_index!(
- @derives [$($derives,)*]
- @attrs [$(#[$attrs])*]
- @type [$type]
- @max [$max]
- @vis [$v]
- @debug_format [$debug_format]
- $name = $constant,);
- );
-
- // Rewrite final const without comma to one that includes comma
- (@derives [$($derives:ident,)*]
- @attrs [$(#[$attrs:meta])*]
- @type [$type:ident]
- @max [$max:expr]
- @vis [$v:vis]
- @debug_format [$debug_format:tt]
- $(#[doc = $doc:expr])*
- const $name:ident = $constant:expr) => (
- $crate::newtype_index!(
- @derives [$($derives,)*]
- @attrs [$(#[$attrs])*]
- @type [$type]
- @max [$max]
- @vis [$v]
- @debug_format [$debug_format]
- $(#[doc = $doc])* const $name = $constant,);
- );
-
- // Replace existing default for max
- (@derives [$($derives:ident,)*]
- @attrs [$(#[$attrs:meta])*]
- @type [$type:ident]
- @max [$_max:expr]
- @vis [$v:vis]
- @debug_format [$debug_format:tt]
- MAX = $max:expr,
- $($tokens:tt)*) => (
- $crate::newtype_index!(
- @derives [$($derives,)*]
- @attrs [$(#[$attrs])*]
- @type [$type]
- @max [$max]
- @vis [$v]
- @debug_format [$debug_format]
- $($tokens)*);
- );
-
- // Replace existing default for debug_format
- (@derives [$($derives:ident,)*]
- @attrs [$(#[$attrs:meta])*]
- @type [$type:ident]
- @max [$max:expr]
- @vis [$v:vis]
- @debug_format [$_debug_format:tt]
- DEBUG_FORMAT = $debug_format:tt,
- $($tokens:tt)*) => (
- $crate::newtype_index!(
- @derives [$($derives,)*]
- @attrs [$(#[$attrs])*]
- @type [$type]
- @max [$max]
- @vis [$v]
- @debug_format [$debug_format]
- $($tokens)*);
- );
-
- // Assign a user-defined constant
- (@derives [$($derives:ident,)*]
- @attrs [$(#[$attrs:meta])*]
- @type [$type:ident]
- @max [$max:expr]
- @vis [$v:vis]
- @debug_format [$debug_format:tt]
- $(#[doc = $doc:expr])*
- const $name:ident = $constant:expr,
- $($tokens:tt)*) => (
- $(#[doc = $doc])*
- $v const $name: $type = $type::from_u32($constant);
- $crate::newtype_index!(
- @derives [$($derives,)*]
- @attrs [$(#[$attrs])*]
- @type [$type]
- @max [$max]
- @vis [$v]
- @debug_format [$debug_format]
- $($tokens)*);
- );
-}
-
#[derive(Clone, PartialEq, Eq, Hash)]
pub struct IndexVec<I: Idx, T> {
pub raw: Vec<T>,
projects / rust.git / blobdiff