Anchor Refcell

demo.rs

// In this example, there are multiple "entites" made from multiple sets of accounts in the context.
// Would like to be able to pass around (partially) mutable entities, is use case for RefCell.

struct MyEntity<'a, 'b> {
  pub &'a mut entity,
  pub &'b ata
}

#[derive(Accounts)]                 
pub struct MyContext<'info> {
  pub entity0: Account<'info, u64>,
  pub entity0_ata: Account<'info, token::TokenAccount>,
    
  pub entity1: Account<'info, u64>,
  pub entity1_ata: Account<'info, token::TokenAccount>
}
  
impl<'info> MyContext<'info> {
  fn get_entity0(&mut self) -> MyEntity { entity: &self.entity0, ata: &mut self.entity0_ata } // Bad borrows
  fn get_entity1(&mut self) -> MyEntity { entity: &self.entity1, ata: &mut self.entity1_ata }
}
 
fn do_something_with_entity(ctx: &ctx, entity: mut MyEntity) {}

#[program]
pub mod my_program {
  use super::*;
   
  fn do_with_entity(ctx: Context<...>) -> Result<()> {
    do_something_with_entity(&ctx, ctx.get_entity0());
    do_something_with_entity(&ctx, ctx.get_entity1());
  }
}