sized-data

Rust trait and derive macro for calculating struct sizes in Solana programs using the Anchor framework.

Overview

sized-data provides compile-time size calculations for Solana program data structures. It's particularly useful when working with account data in Anchor programs where you need to know exact sizes for account initialization.

Usage

Add to your Cargo.toml:

[dependencies]
sized-data = "0.1.1"

Example usage:

use sized_data::SizedData;
use anchor_lang::prelude::*;

#[derive(SizedData)]
pub struct UserAccount {
    pub authority: Pubkey,
    pub counter: u64,
    pub data: [u8; 32],
}

// Initialize account with correct size
#[derive(Accounts)]
pub struct Initialize<'info> {
    #[account(
        init,
        payer = user,
        space = UserAccount::size_padded() // Uses padded size for Anchor
    )]
    pub user_account: Account<'info, UserAccount>,
    #[account(mut)]
    pub user: Signer<'info>,
    pub system_program: Program<'info, System>,
}

Features

• Automatic size calculation for structs
• Built-in implementations for common Solana types (Pubkey, u64, u8, [u8; 32])
• Padded size calculation (adds 8 bytes for Anchor's discriminator)
• Zero-cost abstraction - all calculations done at compile time

Size Implementations

Requirements

• Rust 1.83.0 or later
• anchor-lang 0.30.1 or later

License

MIT License

For more details, visit GitHub Repository