Trait Discriminator

pub trait Discriminator {
    const DISCRIMINATOR: &'static [u8];
}

Unique identifier for a type.

This is not a trait you should derive manually, as various Anchor macros already derive it internally.

Prior to Anchor v0.31, discriminators were always 8 bytes in size. However, starting with Anchor v0.31, it is possible to override the default discriminators, and discriminator length is no longer fixed, which means this trait can also be implemented for non-Anchor programs.

It’s important that the discriminator is always unique for the type you’re implementing it for. While the discriminator can be at any length (including zero), the IDL generation does not currently allow empty discriminators for safety and convenience reasons. However, the trait definition still allows empty discriminators because some non-Anchor programs, e.g. the SPL Token program, don’t have account discriminators. In that case, safety checks should never depend on the discriminator.

Required Associated Constants

const DISCRIMINATOR: &'static [u8]

Discriminator slice.

See Discriminator trait documentation for more information.

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.

Implementations on Foreign Types

impl Discriminator for Append

const DISCRIMINATOR: &'static [u8]

impl Discriminator for CloseEmptyTree

const DISCRIMINATOR: &'static [u8]

impl Discriminator for InitEmptyMerkleTree

const DISCRIMINATOR: &'static [u8]

impl Discriminator for InsertOrAppend

const DISCRIMINATOR: &'static [u8]

impl Discriminator for ReplaceLeaf

const DISCRIMINATOR: &'static [u8]

impl Discriminator for TransferAuthority

const DISCRIMINATOR: &'static [u8]

impl Discriminator for VerifyLeaf

const DISCRIMINATOR: &'static [u8]

Implementors