Macro declare_id 

macro_rules! declare_id {
    ($address:expr) => { ... };
}

Convenience macro to declare a static program ID and helper functions.

Input: a single literal base58 string representation of a program’s ID.

This generates:

• A const ID: Pubkey — the program ID, decoded at compile time.
• A fn check_id(id: &Pubkey) -> bool — returns true if the given pubkey matches.
• A const fn id() -> Pubkey — returns the program ID.

Example

use arch_program::declare_id;

declare_id!("MyProgram111111111111111111111111111111111");

assert_eq!(id(), ID);
assert!(check_id(&id()));