bitflags::traits

Trait Flags

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pub trait Flags: Sized + 'static {
    type Bits: Bits;

    const FLAGS: &'static [Flag<Self>];
Show 24 methods // Required methods fn bits(&self) -> Self::Bits; fn from_bits_retain(bits: Self::Bits) -> Self; // Provided methods fn empty() -> Self { ... } fn all() -> Self { ... } fn contains_unknown_bits(&self) -> bool { ... } fn from_bits(bits: Self::Bits) -> Option<Self> { ... } fn from_bits_truncate(bits: Self::Bits) -> Self { ... } fn from_name(name: &str) -> Option<Self> { ... } fn iter(&self) -> Iter<Self> { ... } fn iter_names(&self) -> IterNames<Self> { ... } fn is_empty(&self) -> bool { ... } fn is_all(&self) -> bool { ... } fn intersects(&self, other: Self) -> bool where Self: Sized { ... } fn contains(&self, other: Self) -> bool where Self: Sized { ... } fn truncate(&mut self) where Self: Sized { ... } fn insert(&mut self, other: Self) where Self: Sized { ... } fn remove(&mut self, other: Self) where Self: Sized { ... } fn toggle(&mut self, other: Self) where Self: Sized { ... } fn set(&mut self, other: Self, value: bool) where Self: Sized { ... } fn intersection(self, other: Self) -> Self { ... } fn union(self, other: Self) -> Self { ... } fn difference(self, other: Self) -> Self { ... } fn symmetric_difference(self, other: Self) -> Self { ... } fn complement(self) -> Self { ... }
}
Expand description

A set of defined flags using a bits type as storage.

§Implementing Flags

This trait is implemented by the bitflags macro:

use bitflags::bitflags;

bitflags! {
    struct MyFlags: u8 {
        const A = 1;
        const B = 1 << 1;
    }
}

It can also be implemented manually:

use bitflags::{Flag, Flags};

struct MyFlags(u8);

impl Flags for MyFlags {
    const FLAGS: &'static [Flag<Self>] = &[
        Flag::new("A", MyFlags(1)),
        Flag::new("B", MyFlags(1 << 1)),
    ];

    type Bits = u8;

    fn from_bits_retain(bits: Self::Bits) -> Self {
        MyFlags(bits)
    }

    fn bits(&self) -> Self::Bits {
        self.0
    }
}

§Using Flags

The Flags trait can be used generically to work with any flags types. In this example, we can count the number of defined named flags:

fn defined_flags<F: Flags>() -> usize {
    F::FLAGS.iter().filter(|f| f.is_named()).count()
}

bitflags! {
    struct MyFlags: u8 {
        const A = 1;
        const B = 1 << 1;
        const C = 1 << 2;

        const _ = !0;
    }
}

assert_eq!(3, defined_flags::<MyFlags>());

Required Associated Constants§

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const FLAGS: &'static [Flag<Self>]

The set of defined flags.

Required Associated Types§

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type Bits: Bits

The underlying bits type.

Required Methods§

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fn bits(&self) -> Self::Bits

Get the underlying bits value.

The returned value is exactly the bits set in this flags value.

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fn from_bits_retain(bits: Self::Bits) -> Self

Convert from a bits value exactly.

Provided Methods§

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fn empty() -> Self

Get a flags value with all bits unset.

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fn all() -> Self

Get a flags value with all known bits set.

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fn contains_unknown_bits(&self) -> bool

This method will return true if any unknown bits are set.

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fn from_bits(bits: Self::Bits) -> Option<Self>

Convert from a bits value.

This method will return None if any unknown bits are set.

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fn from_bits_truncate(bits: Self::Bits) -> Self

Convert from a bits value, unsetting any unknown bits.

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fn from_name(name: &str) -> Option<Self>

Get a flags value with the bits of a flag with the given name set.

This method will return None if name is empty or doesn’t correspond to any named flag.

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fn iter(&self) -> Iter<Self>

Yield a set of contained flags values.

Each yielded flags value will correspond to a defined named flag. Any unknown bits will be yielded together as a final flags value.

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fn iter_names(&self) -> IterNames<Self>

Yield a set of contained named flags values.

This method is like Flags::iter, except only yields bits in contained named flags. Any unknown bits, or bits not corresponding to a contained flag will not be yielded.

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fn is_empty(&self) -> bool

Whether all bits in this flags value are unset.

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fn is_all(&self) -> bool

Whether all known bits in this flags value are set.

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fn intersects(&self, other: Self) -> bool
where Self: Sized,

Whether any set bits in a source flags value are also set in a target flags value.

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fn contains(&self, other: Self) -> bool
where Self: Sized,

Whether all set bits in a source flags value are also set in a target flags value.

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fn truncate(&mut self)
where Self: Sized,

Remove any unknown bits from the flags.

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fn insert(&mut self, other: Self)
where Self: Sized,

The bitwise or (|) of the bits in two flags values.

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fn remove(&mut self, other: Self)
where Self: Sized,

The intersection of a source flags value with the complement of a target flags value (&!).

This method is not equivalent to self & !other when other has unknown bits set. remove won’t truncate other, but the ! operator will.

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fn toggle(&mut self, other: Self)
where Self: Sized,

The bitwise exclusive-or (^) of the bits in two flags values.

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fn set(&mut self, other: Self, value: bool)
where Self: Sized,

Call Flags::insert when value is true or Flags::remove when value is false.

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fn intersection(self, other: Self) -> Self

The bitwise and (&) of the bits in two flags values.

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fn union(self, other: Self) -> Self

The bitwise or (|) of the bits in two flags values.

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fn difference(self, other: Self) -> Self

The intersection of a source flags value with the complement of a target flags value (&!).

This method is not equivalent to self & !other when other has unknown bits set. difference won’t truncate other, but the ! operator will.

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fn symmetric_difference(self, other: Self) -> Self

The bitwise exclusive-or (^) of the bits in two flags values.

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fn complement(self) -> Self

The bitwise negation (!) of the bits in a flags value, truncating the result.

Dyn Compatibility§

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Implementors§

impl Flags for Flags

impl Flags for Sense

impl Flags for PointFlags

impl Flags for FileTest

impl Flags for LogLevels

impl Flags for ParamFlags

impl Flags for SpawnFlags

impl Flags for TypeFlags

impl Flags for UsageFlags

impl Flags for BinFlags

impl Flags for ClockFlags

impl Flags for MetaFlags

impl Flags for PadFlags

impl Flags for ParseFlags

impl Flags for SeekFlags

impl Flags for StreamType

impl Flags for AudioFlags

impl Flags for GLAPI

impl Flags for GLPlatform

impl Flags for VideoFlags

impl Flags for EventMask

impl Flags for WatchMask

impl Flags for Modifiers

impl Flags for Features

impl Flags for RayFlag

impl Flags for Barrier

impl Flags for RayFlag

impl Flags for ExitFlags

impl Flags for GlobalUse

impl Flags for TypeFlags

impl Flags for AtFlags

impl Flags for EpollFlags

impl Flags for EfdFlags

impl Flags for SaFlags

impl Flags for SfdFlags

impl Flags for Extensions

impl Flags for MountFlags

impl Flags for EventFlags

impl Flags for PollFlags

impl Flags for ReadFlags

impl Flags for WatchFlags

impl Flags for Access

impl Flags for AtFlags

impl Flags for IFlags

impl Flags for MemfdFlags

impl Flags for Mode

impl Flags for OFlags

impl Flags for SealFlags

impl Flags for StatxFlags

impl Flags for XattrFlags

impl Flags for DupFlags

impl Flags for FdFlags

impl Flags for RecvFlags

impl Flags for SendFlags

impl Flags for PipeFlags

impl Flags for PidfdFlags

impl Flags for ShmOFlags

impl Flags for Flags

impl Flags for NodeFlags

impl Flags for CapFlags

impl Flags for Globals

impl Flags for Anchor

impl Flags for RayFlags

impl Flags for ColorFlags

impl Flags for OriginSet

impl Flags for CalcUnits

impl Flags for AlignFlags

impl Flags for Contain

impl Flags for DndAction

impl Flags for Mode

impl Flags for Capability

impl Flags for Resize

impl Flags for Transient

impl Flags for Options

impl Flags for State

impl Flags for Flags

impl Flags for Kind

impl Flags for Capability

impl Flags for Capability

impl Flags for Anchor

impl Flags for Flags

impl Flags for MaskFlags

impl Flags for QuadFlags

impl Flags for BrushFlags

impl Flags for BlitReason

impl Flags for ClearCache

impl Flags for SliceFlags

impl Flags for ItemFlags

impl Flags for DebugFlags

impl Flags for Backends

impl Flags for BufferUses

impl Flags for Features