src/traits.rs - platform/external/rust/crates/bitflags - Git at Google

 use core::{fmt, ops::{BitAnd, BitOr, BitXor, Not}};

 use crate::{parser::{ParseError, ParseHex, WriteHex}, iter};

 /// Metadata for an individual flag.
 pub struct Flag<B> {
     name: &'static str,
     value: B,
 }

 impl<B> Flag<B> {
     /// Create a new flag with the given name and value.
     pub const fn new(name: &'static str, value: B) -> Self {
         Flag { name, value }
     }

     /// Get the name of this flag.
     pub const fn name(&self) -> &'static str {
         self.name
     }

     /// Get the value of this flag.
     pub const fn value(&self) -> &B {
         &self.value
     }
 }

 /// A set of flags.
 ///
 /// This trait is automatically implemented for flags types defined using the `bitflags!` macro.
 /// It can also be implemented manually for custom flags types.
 pub trait Flags: Sized + 'static {
     /// The set of available flags and their names.
     const FLAGS: &'static [Flag<Self>];

     /// The underlying storage type.
     type Bits: Bits;

     /// Returns an empty set of flags.
     fn empty() -> Self {
         Self::from_bits_retain(Self::Bits::EMPTY)
     }

     /// Returns the set containing all flags.
     fn all() -> Self {
         Self::from_bits_truncate(Self::Bits::ALL)
     }

     /// Returns the raw value of the flags currently stored.
     fn bits(&self) -> Self::Bits;

     /// Convert from underlying bit representation, unless that
     /// representation contains bits that do not correspond to a flag.
     ///
     /// Note that each [multi-bit flag] is treated as a unit for this comparison.
     ///
     /// [multi-bit flag]: index.html#multi-bit-flags
     fn from_bits(bits: Self::Bits) -> Option<Self> {
         let truncated = Self::from_bits_truncate(bits);

         if truncated.bits() == bits {
             Some(truncated)
         } else {
             None
         }
     }

     /// Convert from underlying bit representation, dropping any bits
     /// that do not correspond to flags.
     ///
     /// Note that each [multi-bit flag] is treated as a unit for this comparison.
     ///
     /// [multi-bit flag]: index.html#multi-bit-flags
     fn from_bits_truncate(bits: Self::Bits) -> Self {
         if bits == Self::Bits::EMPTY {
             return Self::empty();
         }

         let mut truncated = Self::Bits::EMPTY;

         for flag in Self::FLAGS.iter() {
             let flag = flag.value();

             if bits & flag.bits() == flag.bits() {
                 truncated = truncated | flag.bits();
             }
         }

         Self::from_bits_retain(truncated)
     }

     /// Convert from underlying bit representation, preserving all
     /// bits (even those not corresponding to a defined flag).
     fn from_bits_retain(bits: Self::Bits) -> Self;

     /// Get the flag for a particular name.
     fn from_name(name: &str) -> Option<Self> {
         for flag in Self::FLAGS {
             if flag.name() == name {
                 return Some(Self::from_bits_retain(flag.value().bits()))
             }
         }

         None
     }

     /// Iterate over enabled flag values.
     fn iter(&self) -> iter::Iter<Self> {
         iter::Iter::new(self)
     }

     /// Iterate over the raw names and bits for enabled flag values.
     fn iter_names(&self) -> iter::IterNames<Self> {
         iter::IterNames::new(self)
     }

     /// Returns `true` if no flags are currently stored.
     fn is_empty(&self) -> bool {
         self.bits() == Self::Bits::EMPTY
     }

     /// Returns `true` if all flags are currently set.
     fn is_all(&self) -> bool {
         // NOTE: We check against `Self::all` here, not `Self::Bits::ALL`
         // because the set of all flags may not use all bits
         Self::all().bits() | self.bits() == self.bits()
     }

     /// Returns `true` if there are flags common to both `self` and `other`.
     fn intersects(&self, other: Self) -> bool
     where
         Self: Sized,
     {
         self.bits() & other.bits() != Self::Bits::EMPTY
     }

     /// Returns `true` if all of the flags in `other` are contained within `self`.
     fn contains(&self, other: Self) -> bool
     where
         Self: Sized,
     {
         self.bits() & other.bits() == other.bits()
     }

     /// Inserts the specified flags in-place.
     fn insert(&mut self, other: Self)
     where
         Self: Sized,
     {
         *self = Self::from_bits_retain(self.bits() | other.bits());
     }

     /// Removes the specified flags in-place.
     fn remove(&mut self, other: Self)
     where
         Self: Sized,
     {
         *self = Self::from_bits_retain(self.bits() & !other.bits());
     }

     /// Toggles the specified flags in-place.
     fn toggle(&mut self, other: Self)
     where
         Self: Sized,
     {
         *self = Self::from_bits_retain(self.bits() ^ other.bits());
     }

     /// Inserts or removes the specified flags depending on the passed value.
     fn set(&mut self, other: Self, value: bool)
     where
         Self: Sized,
     {
         if value {
             self.insert(other);
         } else {
             self.remove(other);
         }
     }

     /// Returns the intersection between the flags in `self` and
     /// `other`.
     ///
     /// Specifically, the returned set contains only the flags which are
     /// present in *both* `self` *and* `other`.
     #[must_use]
     fn intersection(self, other: Self) -> Self {
         Self::from_bits_retain(self.bits() & other.bits())
     }

     /// Returns the union of between the flags in `self` and `other`.
     ///
     /// Specifically, the returned set contains all flags which are
     /// present in *either* `self` *or* `other`, including any which are
     /// present in both (see [`Self::symmetric_difference`] if that
     /// is undesirable).
     #[must_use]
     fn union(self, other: Self) -> Self {
         Self::from_bits_retain(self.bits() | other.bits())
     }

     /// Returns the difference between the flags in `self` and `other`.
     ///
     /// Specifically, the returned set contains all flags present in
     /// `self`, except for the ones present in `other`.
     ///
     /// It is also conceptually equivalent to the "bit-clear" operation:
     /// `flags & !other` (and this syntax is also supported).
     #[must_use]
     fn difference(self, other: Self) -> Self {
         Self::from_bits_retain(self.bits() & !other.bits())
     }

     /// Returns the [symmetric difference][sym-diff] between the flags
     /// in `self` and `other`.
     ///
     /// Specifically, the returned set contains the flags present which
     /// are present in `self` or `other`, but that are not present in
     /// both. Equivalently, it contains the flags present in *exactly
     /// one* of the sets `self` and `other`.
     ///
     /// [sym-diff]: https://en.wikipedia.org/wiki/Symmetric_difference
     #[must_use]
     fn symmetric_difference(self, other: Self) -> Self {
         Self::from_bits_retain(self.bits() ^ other.bits())
     }

     /// Returns the complement of this set of flags.
     ///
     /// Specifically, the returned set contains all the flags which are
     /// not set in `self`, but which are allowed for this type.
     #[must_use]
     fn complement(self) -> Self {
         Self::from_bits_truncate(!self.bits())
     }
 }

 /// Underlying storage for a flags type.
 pub trait Bits:
     Clone
     + Copy
     + PartialEq
     + BitAnd<Output = Self>
     + BitOr<Output = Self>
     + BitXor<Output = Self>
     + Not<Output = Self>
     + Sized
     + 'static
 {
     /// The value of `Self` where no bits are set.
     const EMPTY: Self;

     /// The value of `Self` where all bits are set.
     const ALL: Self;
 }

 // Not re-exported: prevent custom `Bits` impls being used in the `bitflags!` macro,
 // or they may fail to compile based on crate features
 pub trait Primitive {}

 macro_rules! impl_bits {
     ($($u:ty, $i:ty,)*) => {
         $(
             impl Bits for $u {
                 const EMPTY: $u = 0;
                 const ALL: $u = <$u>::MAX;
             }

             impl Bits for $i {
                 const EMPTY: $i = 0;
                 const ALL: $i = <$u>::MAX as $i;
             }

             impl ParseHex for $u {
                 fn parse_hex(input: &str) -> Result<Self, ParseError> {
                     <$u>::from_str_radix(input, 16).map_err(|_| ParseError::invalid_hex_flag(input))
                 }
             }

             impl ParseHex for $i {
                 fn parse_hex(input: &str) -> Result<Self, ParseError> {
                     <$i>::from_str_radix(input, 16).map_err(|_| ParseError::invalid_hex_flag(input))
                 }
             }

             impl WriteHex for $u {
                 fn write_hex<W: fmt::Write>(&self, mut writer: W) -> fmt::Result {
                     write!(writer, "{:x}", self)
                 }
             }

             impl WriteHex for $i {
                 fn write_hex<W: fmt::Write>(&self, mut writer: W) -> fmt::Result {
                     write!(writer, "{:x}", self)
                 }
             }

             impl Primitive for $i {}
             impl Primitive for $u {}
         )*
     }
 }

 impl_bits! {
     u8, i8,
     u16, i16,
     u32, i32,
     u64, i64,
     u128, i128,
     usize, isize,
 }

 /// A trait for referencing the `bitflags`-owned internal type
 /// without exposing it publicly.
 pub trait PublicFlags {
     /// The type of the underlying storage.
     type Primitive: Primitive;

     /// The type of the internal field on the generated flags type.
     type Internal;
 }

 #[deprecated(note = "use the `Flags` trait instead")]
 pub trait BitFlags: ImplementedByBitFlagsMacro + Flags {
     /// An iterator over enabled flags in an instance of the type.
     type Iter: Iterator<Item = Self>;

     /// An iterator over the raw names and bits for enabled flags in an instance of the type.
     type IterNames: Iterator<Item = (&'static str, Self)>;
 }

 #[allow(deprecated)]
 impl<B: Flags> BitFlags for B {
     type Iter = iter::Iter<Self>;
     type IterNames = iter::IterNames<Self>;
 }

 impl<B: Flags> ImplementedByBitFlagsMacro for B {}

 /// A marker trait that signals that an implementation of `BitFlags` came from the `bitflags!` macro.
 ///
 /// There's nothing stopping an end-user from implementing this trait, but we don't guarantee their
 /// manual implementations won't break between non-breaking releases.
 #[doc(hidden)]
 pub trait ImplementedByBitFlagsMacro {}

 pub(crate) mod __private {
     pub use super::{ImplementedByBitFlagsMacro, PublicFlags};
 }
	use core::{fmt, ops::{BitAnd, BitOr, BitXor, Not}};

	use crate::{parser::{ParseError, ParseHex, WriteHex}, iter};

	/// Metadata for an individual flag.
	pub struct Flag<B> {
	name: &'static str,
	value: B,
	}

	impl<B> Flag<B> {
	/// Create a new flag with the given name and value.
	pub const fn new(name: &'static str, value: B) -> Self {
	Flag { name, value }
	}

	/// Get the name of this flag.
	pub const fn name(&self) -> &'static str {
	self.name
	}

	/// Get the value of this flag.
	pub const fn value(&self) -> &B {
	&self.value
	}
	}

	/// A set of flags.
	///
	/// This trait is automatically implemented for flags types defined using the `bitflags!` macro.
	/// It can also be implemented manually for custom flags types.
	pub trait Flags: Sized + 'static {
	/// The set of available flags and their names.
	const FLAGS: &'static [Flag<Self>];

	/// The underlying storage type.
	type Bits: Bits;

	/// Returns an empty set of flags.
	fn empty() -> Self {
	Self::from_bits_retain(Self::Bits::EMPTY)
	}

	/// Returns the set containing all flags.
	fn all() -> Self {
	Self::from_bits_truncate(Self::Bits::ALL)
	}

	/// Returns the raw value of the flags currently stored.
	fn bits(&self) -> Self::Bits;

	/// Convert from underlying bit representation, unless that
	/// representation contains bits that do not correspond to a flag.
	///
	/// Note that each [multi-bit flag] is treated as a unit for this comparison.
	///
	/// [multi-bit flag]: index.html#multi-bit-flags
	fn from_bits(bits: Self::Bits) -> Option<Self> {
	let truncated = Self::from_bits_truncate(bits);

	if truncated.bits() == bits {
	Some(truncated)
	} else {
	None
	}
	}

	/// Convert from underlying bit representation, dropping any bits
	/// that do not correspond to flags.
	///
	/// Note that each [multi-bit flag] is treated as a unit for this comparison.
	///
	/// [multi-bit flag]: index.html#multi-bit-flags
	fn from_bits_truncate(bits: Self::Bits) -> Self {
	if bits == Self::Bits::EMPTY {
	return Self::empty();
	}

	let mut truncated = Self::Bits::EMPTY;

	for flag in Self::FLAGS.iter() {
	let flag = flag.value();

	if bits & flag.bits() == flag.bits() {
	truncated = truncated \| flag.bits();
	}
	}

	Self::from_bits_retain(truncated)
	}

	/// Convert from underlying bit representation, preserving all
	/// bits (even those not corresponding to a defined flag).
	fn from_bits_retain(bits: Self::Bits) -> Self;

	/// Get the flag for a particular name.
	fn from_name(name: &str) -> Option<Self> {
	for flag in Self::FLAGS {
	if flag.name() == name {
	return Some(Self::from_bits_retain(flag.value().bits()))
	}
	}

	None
	}

	/// Iterate over enabled flag values.
	fn iter(&self) -> iter::Iter<Self> {
	iter::Iter::new(self)
	}

	/// Iterate over the raw names and bits for enabled flag values.
	fn iter_names(&self) -> iter::IterNames<Self> {
	iter::IterNames::new(self)
	}

	/// Returns `true` if no flags are currently stored.
	fn is_empty(&self) -> bool {
	self.bits() == Self::Bits::EMPTY
	}

	/// Returns `true` if all flags are currently set.
	fn is_all(&self) -> bool {
	// NOTE: We check against `Self::all` here, not `Self::Bits::ALL`
	// because the set of all flags may not use all bits
	Self::all().bits() \| self.bits() == self.bits()
	}

	/// Returns `true` if there are flags common to both `self` and `other`.
	fn intersects(&self, other: Self) -> bool
	where
	Self: Sized,
	{
	self.bits() & other.bits() != Self::Bits::EMPTY
	}

	/// Returns `true` if all of the flags in `other` are contained within `self`.
	fn contains(&self, other: Self) -> bool
	where
	Self: Sized,
	{
	self.bits() & other.bits() == other.bits()
	}

	/// Inserts the specified flags in-place.
	fn insert(&mut self, other: Self)
	where
	Self: Sized,
	{
	*self = Self::from_bits_retain(self.bits() \| other.bits());
	}

	/// Removes the specified flags in-place.
	fn remove(&mut self, other: Self)
	where
	Self: Sized,
	{
	*self = Self::from_bits_retain(self.bits() & !other.bits());
	}

	/// Toggles the specified flags in-place.
	fn toggle(&mut self, other: Self)
	where
	Self: Sized,
	{
	*self = Self::from_bits_retain(self.bits() ^ other.bits());
	}

	/// Inserts or removes the specified flags depending on the passed value.
	fn set(&mut self, other: Self, value: bool)
	where
	Self: Sized,
	{
	if value {
	self.insert(other);
	} else {
	self.remove(other);
	}
	}

	/// Returns the intersection between the flags in `self` and
	/// `other`.
	///
	/// Specifically, the returned set contains only the flags which are
	/// present in both `self` and `other`.
	#[must_use]
	fn intersection(self, other: Self) -> Self {
	Self::from_bits_retain(self.bits() & other.bits())
	}

	/// Returns the union of between the flags in `self` and `other`.
	///
	/// Specifically, the returned set contains all flags which are
	/// present in either `self` or `other`, including any which are
	/// present in both (see [`Self::symmetric_difference`] if that
	/// is undesirable).
	#[must_use]
	fn union(self, other: Self) -> Self {
	Self::from_bits_retain(self.bits() \| other.bits())
	}

	/// Returns the difference between the flags in `self` and `other`.
	///
	/// Specifically, the returned set contains all flags present in
	/// `self`, except for the ones present in `other`.
	///
	/// It is also conceptually equivalent to the "bit-clear" operation:
	/// `flags & !other` (and this syntax is also supported).
	#[must_use]
	fn difference(self, other: Self) -> Self {
	Self::from_bits_retain(self.bits() & !other.bits())
	}

	/// Returns the [symmetric difference][sym-diff] between the flags
	/// in `self` and `other`.
	///
	/// Specifically, the returned set contains the flags present which
	/// are present in `self` or `other`, but that are not present in
	/// both. Equivalently, it contains the flags present in *exactly
	/// one* of the sets `self` and `other`.
	///
	/// [sym-diff]: https://en.wikipedia.org/wiki/Symmetric_difference
	#[must_use]
	fn symmetric_difference(self, other: Self) -> Self {
	Self::from_bits_retain(self.bits() ^ other.bits())
	}

	/// Returns the complement of this set of flags.
	///
	/// Specifically, the returned set contains all the flags which are
	/// not set in `self`, but which are allowed for this type.
	#[must_use]
	fn complement(self) -> Self {
	Self::from_bits_truncate(!self.bits())
	}
	}

	/// Underlying storage for a flags type.
	pub trait Bits:
	Clone
	+ Copy
	+ PartialEq
	+ BitAnd<Output = Self>
	+ BitOr<Output = Self>
	+ BitXor<Output = Self>
	+ Not<Output = Self>
	+ Sized
	+ 'static
	{
	/// The value of `Self` where no bits are set.
	const EMPTY: Self;

	/// The value of `Self` where all bits are set.
	const ALL: Self;
	}

	// Not re-exported: prevent custom `Bits` impls being used in the `bitflags!` macro,
	// or they may fail to compile based on crate features
	pub trait Primitive {}

	macro_rules! impl_bits {
	($($u:ty, $i:ty,)*) => {
	$(
	impl Bits for $u {
	const EMPTY: $u = 0;
	const ALL: $u = <$u>::MAX;
	}

	impl Bits for $i {
	const EMPTY: $i = 0;
	const ALL: $i = <$u>::MAX as $i;
	}

	impl ParseHex for $u {
	fn parse_hex(input: &str) -> Result<Self, ParseError> {
	<$u>::from_str_radix(input, 16).map_err(\|_\| ParseError::invalid_hex_flag(input))
	}
	}

	impl ParseHex for $i {
	fn parse_hex(input: &str) -> Result<Self, ParseError> {
	<$i>::from_str_radix(input, 16).map_err(\|_\| ParseError::invalid_hex_flag(input))
	}
	}

	impl WriteHex for $u {
	fn write_hex<W: fmt::Write>(&self, mut writer: W) -> fmt::Result {
	write!(writer, "{:x}", self)
	}
	}

	impl WriteHex for $i {
	fn write_hex<W: fmt::Write>(&self, mut writer: W) -> fmt::Result {
	write!(writer, "{:x}", self)
	}
	}

	impl Primitive for $i {}
	impl Primitive for $u {}
	)*
	}
	}

	impl_bits! {
	u8, i8,
	u16, i16,
	u32, i32,
	u64, i64,
	u128, i128,
	usize, isize,
	}

	/// A trait for referencing the `bitflags`-owned internal type
	/// without exposing it publicly.
	pub trait PublicFlags {
	/// The type of the underlying storage.
	type Primitive: Primitive;

	/// The type of the internal field on the generated flags type.
	type Internal;
	}

	#[deprecated(note = "use the `Flags` trait instead")]
	pub trait BitFlags: ImplementedByBitFlagsMacro + Flags {
	/// An iterator over enabled flags in an instance of the type.
	type Iter: Iterator<Item = Self>;

	/// An iterator over the raw names and bits for enabled flags in an instance of the type.
	type IterNames: Iterator<Item = (&'static str, Self)>;
	}

	#[allow(deprecated)]
	impl<B: Flags> BitFlags for B {
	type Iter = iter::Iter<Self>;
	type IterNames = iter::IterNames<Self>;
	}

	impl<B: Flags> ImplementedByBitFlagsMacro for B {}

	/// A marker trait that signals that an implementation of `BitFlags` came from the `bitflags!` macro.
	///
	/// There's nothing stopping an end-user from implementing this trait, but we don't guarantee their
	/// manual implementations won't break between non-breaking releases.
	#[doc(hidden)]
	pub trait ImplementedByBitFlagsMacro {}

	pub(crate) mod __private {
	pub use super::{ImplementedByBitFlagsMacro, PublicFlags};
	}