Trait rustbus::wire::marshal::traits::Signature

pub trait Signature {
    fn signature() -> Type;
    fn alignment() -> usize;

    unsafe fn valid_slice(_bo: ByteOrder) -> bool { ... }
    fn sig_str(s_buf: &mut SignatureBuffer) { ... }
}

Required methods

fn signature() -> Type

fn alignment() -> usize

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Provided methods

unsafe fn valid_slice(_bo: ByteOrder) -> bool

If this returns true, it indicates that for implementing type T, Rust’s [T] is identical to DBus’s array format and can be copied into a message after aligning the first element.

The default implementation is false but can be overridden for a performance gain if it is valid.

Safety

Calls to this function should always be safe. Implementors should respect this property. The reason this method is unsafe is to indicate to people implementing Signature that overriding it has the potential to induce unsound behavior if the following rules aren’t followed:

1. The type T implementing Signature must be Copy.
2. The size of T must be equivalent to it’s DBus alignment (see here).
3. Every possible bit-pattern must represent a valid instance of T. For example std::num::NonZeroU32 does not meet this requirement 0 is invalid.
4. The type should not contain an Fd receieved from the message. When implementing Unmarshal the type should only dependent the 'buf lifetime. It should never require the use of 'fds.

Notes

• This method exists because of limitiation with Rust type system. Should #[feature(specialization)] ever become stablized this will hopefully be unnecessary.
• This method should use the ByteOrder to check if it matches native order before returning true. ByteOrder::NATIVE can be used to detect the native order.

fn sig_str(s_buf: &mut SignatureBuffer)

Appends the signature of the type to the SignatureBuffer.

By using SignatureBuffer, implementations of this method can avoid unnecessary allocations by only allocating if a signature is dynamic.

The default implementation of sig_str can be pretty slow. If type, that Signature is being implemented for, has a static (unchanging) signature then overriding this method can have a significant performance benefit when marshal/unmarshalling the type inside variants.

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Implementations on Foreign Types

impl<S: Signature> Signature for &S

fn signature() -> Type

fn alignment() -> usize

impl<E: Signature> Signature for (E,)

fn signature() -> Type

fn alignment() -> usize

impl<E1: Signature, E2: Signature> Signature for (E1, E2)

fn signature() -> Type

fn alignment() -> usize

fn sig_str(s_buf: &mut SignatureBuffer)

impl<E1: Signature, E2: Signature, E3: Signature> Signature for (E1, E2, E3)

fn signature() -> Type

fn alignment() -> usize

fn sig_str(s_buf: &mut SignatureBuffer)

impl<E1: Signature, E2: Signature, E3: Signature, E4: Signature> Signature for (E1, E2, E3, E4)

fn signature() -> Type

fn alignment() -> usize

fn sig_str(s_buf: &mut SignatureBuffer)

impl<E1: Signature, E2: Signature, E3: Signature, E4: Signature, E5: Signature> Signature for (E1, E2, E3, E4, E5)

fn signature() -> Type

fn alignment() -> usize

fn sig_str(s_buf: &mut SignatureBuffer)

impl<E: Signature> Signature for [E]

fn signature() -> Type

fn alignment() -> usize

fn sig_str(s_buf: &mut SignatureBuffer)

impl<E: Signature> Signature for &[E]

fn signature() -> Type

fn alignment() -> usize

fn sig_str(s_buf: &mut SignatureBuffer)

impl<K: Signature, V: Signature> Signature for HashMap<K, V>

fn signature() -> Type

fn alignment() -> usize

impl Signature for u64

fn signature() -> Type

fn alignment() -> usize

unsafe fn valid_slice(bo: ByteOrder) -> bool

fn sig_str(sig: &mut SignatureBuffer)

impl Signature for i64

fn signature() -> Type

fn alignment() -> usize

unsafe fn valid_slice(bo: ByteOrder) -> bool

fn sig_str(sig: &mut SignatureBuffer)

impl Signature for u32

fn signature() -> Type

fn alignment() -> usize

unsafe fn valid_slice(bo: ByteOrder) -> bool

fn sig_str(sig: &mut SignatureBuffer)

impl Signature for i32

fn signature() -> Type

fn alignment() -> usize

unsafe fn valid_slice(bo: ByteOrder) -> bool

fn sig_str(sig: &mut SignatureBuffer)

impl Signature for u16

fn signature() -> Type

fn alignment() -> usize

unsafe fn valid_slice(bo: ByteOrder) -> bool

fn sig_str(sig: &mut SignatureBuffer)

impl Signature for i16

fn signature() -> Type

fn alignment() -> usize

unsafe fn valid_slice(bo: ByteOrder) -> bool

fn sig_str(sig: &mut SignatureBuffer)

impl Signature for u8

fn signature() -> Type

fn alignment() -> usize

unsafe fn valid_slice(_: ByteOrder) -> bool

fn sig_str(sig: &mut SignatureBuffer)

impl Signature for bool

fn signature() -> Type

fn alignment() -> usize

fn sig_str(sig: &mut SignatureBuffer)

impl Signature for String

fn signature() -> Type

fn alignment() -> usize

fn sig_str(sig: &mut SignatureBuffer)

impl Signature for &str

fn signature() -> Type

fn alignment() -> usize

fn sig_str(sig: &mut SignatureBuffer)

impl Signature for &dyn AsRawFd

fn signature() -> Type

fn alignment() -> usize

impl<E: Signature> Signature for Vec<E>

fn signature() -> Type

fn alignment() -> usize

impl<E: Signature + Clone> Signature for Cow<'_, [E]>

fn signature() -> Type

fn alignment() -> usize

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Implementors

impl Signature for UnixFd

fn signature() -> Type

fn alignment() -> usize

impl Signature for Variant<'_, '_>

fn signature() -> Type

fn alignment() -> usize

impl Signature for SignatureWrapper<'_>

fn signature() -> Type

fn alignment() -> usize

fn sig_str(s_buf: &mut SignatureBuffer)

impl<'a, E: Copy + Marshal> Signature for OptimizedMarshal<'a, E>

fn signature() -> Type

fn alignment() -> usize

impl<S: AsRef<str>> Signature for ObjectPath<S>

fn signature() -> Type

fn alignment() -> usize

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