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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-18 02:49:50 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-18 02:49:50 +0000
commit9835e2ae736235810b4ea1c162ca5e65c547e770 (patch)
tree3fcebf40ed70e581d776a8a4c65923e8ec20e026 /vendor/partial_ref/src/macros.rs
parentReleasing progress-linux version 1.70.0+dfsg2-1~progress7.99u1. (diff)
downloadrustc-9835e2ae736235810b4ea1c162ca5e65c547e770.tar.xz
rustc-9835e2ae736235810b4ea1c162ca5e65c547e770.zip
Merging upstream version 1.71.1+dfsg1.
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'vendor/partial_ref/src/macros.rs')
-rw-r--r--vendor/partial_ref/src/macros.rs154
1 files changed, 154 insertions, 0 deletions
diff --git a/vendor/partial_ref/src/macros.rs b/vendor/partial_ref/src/macros.rs
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+/// Declares a [`Part`].
+///
+/// Defines an empty struct type and derives all necessary instances to use it as a marker type for
+/// parts.
+///
+/// This macro can define [`AbstractPart`]s using `part!(PartName);` or `part!(pub PartName);` and
+/// [`Field`] parts using `part!(PartName: FieldType);` or `part!(pub PartName: FieldType);`.
+#[macro_export]
+macro_rules! part {
+ ($part:ident) => { part!(@template $part () () ($crate::AbstractPart)); };
+ (pub $part:ident) => { part!(@template $part () (pub) ($crate::AbstractPart)); };
+ ($part:ident<> : $field:ty) => { part!($part : $field); };
+ (pub $part:ident<> : $field:ty) => { part!(pub $part : $field); };
+ ($part:ident<$($lt:lifetime),*> : $field:ty) => {
+ part!(@template $part ($($lt),*) () ($crate::Field<$field>) ($field));
+ };
+ (pub $part:ident<$($lt:lifetime),*> : $field:ty) => {
+ part!(@template $part ($($lt),*) (pub) ($crate::Field<$field>) ($field));
+ };
+ ($part:ident : $field:ty) => { part!(@template $part () () ($crate::Field<$field>)); };
+ (pub $part:ident : $field:ty) => { part!(@template $part () (pub) ($crate::Field<$field>)); };
+ (@template $part:ident () ($($vis:tt)*) ($($part_type:tt)*)) => {
+ #[derive(Default)]
+ $($vis)* struct $part;
+ impl $crate::Part for $part {
+ type PartType = $($part_type)*;
+ }
+
+ impl $crate::PartSpec<$part> for $part {}
+
+ // TODO maybe constrain InnerPart
+ impl<InnerPart: $crate::Part> ::std::ops::BitOr<InnerPart> for $part {
+ type Output = $crate::Nested<$part, InnerPart>;
+
+ fn bitor(self, _rhs: InnerPart) -> Self::Output {
+ std::default::Default::default()
+ }
+ }
+ };
+ (@template $part:ident ($($lt:lifetime),*) ($($vis:tt)*) ($($part_type:tt)*) ($field:ty)) => {
+ #[derive(Default)]
+ $($vis)* struct $part<$($lt),*> {
+ phantom: ::std::marker::PhantomData<$field>,
+ }
+
+ #[allow(non_upper_case_globals)]
+ $($vis)* const $part: $part = $part { phantom: ::std::marker::PhantomData };
+
+ impl<$($lt),*> $crate::Part for $part<$($lt),*> {
+ type PartType = $($part_type)*;
+ }
+
+ part!(@spec_template $part ($($lt),*));
+
+ // TODO maybe constrain InnerPart
+ impl<$($lt),*, InnerPart: $crate::Part> ::std::ops::BitOr<InnerPart> for $part<$($lt),*> {
+ type Output = $crate::Nested<$part<$($lt),*>, InnerPart>;
+
+ fn bitor(self, _rhs: InnerPart) -> Self::Output {
+ std::default::Default::default()
+ }
+ }
+ };
+ (@spec_template $part:ident ($l:lifetime)) => {
+ impl<'a, 'b> $crate::PartSpec<$part<'a>> for $part<'b> {}
+ };
+ (@spec_template $part:ident ($l1:lifetime, $l2:lifetime)) => {
+ impl<'a1, 'a2, 'b1, 'b2> $crate::PartSpec<$part<'a1, 'a2>> for $part<'b1, 'b2> {}
+ };
+ (@spec_template $part:ident ($l1:lifetime, $l2:lifetime, $l3:lifetime)) => {
+ impl<'a1, 'a2, 'a3, 'b1, 'b2, 'b3>
+ $crate::PartSpec<$part<'a1, 'a2, 'a3>>
+ for $part<'b1, 'b2, 'b3> {}
+ };
+ (@spec_template $part:ident ($($tt:tt)*)) => {
+ // TODO avoid this limitation
+ compile_error!("parts with more than 3 lifetimes are not supported yet");
+ };
+}
+
+/// Concise syntax for partial reference types.
+///
+/// The first parameter is the reference target type, optionally preceded by a lifetime. The
+/// following parameters are the referenced parts, each optionally preceded by the keyword `mut` to
+/// indicate a mutable reference to that part. Nested parts can be specified using the pipe syntax
+/// of [`nested_part`].
+///
+/// Examples:
+/// * `partial!(Ty, PartA)` is `Const<PartA, Ref<Ty>>`
+/// * `partial!('a Ty, mut PartA)` is `Mut<PartA, Ref<'a, Ty>>`
+/// * `partial!(Ty, PartA, PartB, mut PartC)` is
+/// `Const<PartA, Const<PartB, Mut<PartC, Ref<Ty>>`
+/// * `partial!('a Ty, mut PartA | PartB)` is `Mut<Nested<PartA, PartB>, Ref<'a, Ty>>`
+#[macro_export]
+macro_rules! partial {
+ ($target_lt:lifetime $target:ty) => { $crate::Ref<$target_lt, $target> };
+ ($target_lt:lifetime $target:ty, $($parts:tt)*) => {
+ partial!(@extend $crate::Ref<$target_lt, $target>, $($parts)*)
+ };
+ ($target:ty) => { $crate::Ref<$target> };
+ ($target:ty, $($parts:tt)* ) => {
+ partial!(@extend $crate::Ref<$target>, $($parts)*)
+ };
+ (@extend $target:ty) => {$target};
+ (@extend $target:ty, ) => {$target};
+ (@extend $target:ty, mut $($part:ty)|* , $($rest:tt)*) => {
+ partial!(@extend $crate::Mut<$crate::nested_part!($($part)|*), $target>, $($rest)*)
+ };
+ (@extend $target:ty, mut $($part:ty)|*) => {
+ partial!(@extend $target, mut $($part)|*, )
+ };
+ (@extend $target:ty, $($part:ty)|* , $($rest:tt)*) => {
+ partial!(@extend $crate::Const<$crate::nested_part!($($part)|*), $target>, $($rest)*)
+ };
+ (@extend $target:ty, $($part:ty)|*) => {
+ partial!(@extend $target, $($part)|*, )
+ };
+}
+
+/// Expands `A | B | ... | Z` to `Nested<...Nested<A, B>, ..., Z>`
+///
+/// This mirrors the syntax for the expressions that can be passed to [`PartialRef`]'s part
+/// functions.
+#[macro_export]
+macro_rules! nested_part {
+ ($target:ty) => { $target };
+ ($target:ty | $part:ty) => {
+ $crate::Nested<$target , $part>
+ };
+ ($target:ty | $part:ty | $($subparts:ty)|*) => {
+ nested_part!($crate::Nested<$target , $part> | $($subparts)|*)
+ };
+}
+
+/// Helper macro for splitting a partial reference.
+///
+/// The statement `split_borrow!(target, rest = &(...) expr)` where `...` is a list of parts (same
+/// syntax as used for [`partial`]) splits the partial reference returned by expr and binds the listed
+/// parts to the identifier `target` and the remaining parts to the identifier `rest`. This is done
+/// using [`PartialRef`]'s split_borrow method.
+///
+/// As shorter version is available as `split_borrow!(target = &(...) ident)` which is identical to
+/// `split_borrow!(target, ident = &(...) ident)`. This shadows the existing partial reference with
+/// a new binding.
+#[macro_export]
+macro_rules! split_borrow {
+ ($target:ident = &($($parts:tt)*) $from:ident) => {
+ split_borrow!($target, $from = &($($parts)*) $from)
+ };
+ ($target:ident, $rest:ident = &($($parts:tt)*) $from:expr) => {
+ #[allow(unused_variables, unused_mut)]
+ let (mut $target, mut $rest) = ($from).split_borrow::<partial!(_, $($parts)*), _>();
+ };
+}