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Flags

ark_serialize

Trait Flags 

Source 
pub trait Flags:
    Default
    + Clone
    + Copy
    + Sized {
    const BIT_SIZE: usize;

    // Required methods
    fn u8_bitmask(&self) -> u8;
    fn from_u8(value: u8) -> Option<Self>;

    // Provided method
    fn from_u8_remove_flags(value: &mut u8) -> Option<Self> { ... }
}
Expand description

Represents metadata to be appended to an object’s serialization.

For example, when serializing elliptic curve points, one can use a Flag to represent whether the serialization is the point at infinity, or whether the y coordinate is positive or not. These bits will be appended to the end of the point’s serialization, or included in a new byte, depending on space available.

This is meant to be provided to CanonicalSerializeWithFlags and CanonicalDeserializeWithFlags

Required Associated Constants§

Source

const BIT_SIZE: usize

The number of bits required to encode Self. This should be at most 8.

Required Methods§

Source

fn u8_bitmask(&self) -> u8

Returns a bit mask corresponding to self. For example, if Self contains two variants, there are just two possible bit masks: 0 and 1 << 7.

Source

fn from_u8(value: u8) -> Option<Self>

Tries to read Self from value. Should return None if the Self::BIT_SIZE most-significant bits of value do not correspond to those generated by u8_bitmask.

That is, this method ignores all but the top Self::BIT_SIZE bits, and decides whether these top bits correspond to a bitmask output by u8_bitmask.

Provided Methods§

Source

fn from_u8_remove_flags(value: &mut u8) -> Option<Self>

Convenience method that reads Self from value, just like Self::from_u8, but additionally zeroes out the bits corresponding to the resulting flag in value. If Self::from_u8(*value) would return None, then this method should not modify value.

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§