How to use Tuples in Anchor lang

Question

What am I doing wrong? Is that not how we use tuples in rust?

Account:

#[account]
pub struct UserLedger {
    pub list: Vec<(String, u32)>,
}

Error Message:

Error: Type not found: {"type":{"defined":"(String,u32)"}}

Answer 1

tuples are not implemented in anchor so far (version: 0.27.0 at time of writing), you can use a struct in your case.

#[account]
pub struct UserLedger {
    pub list: Vec<MyTuple>,
}

#[derive(AnchorSerialize, AnchorDeserialize)]
struct MyTuple {
    my_string: String,
    my_u32: u32
}

for an enum as well you are not allowed to use tuples, which is quite common, but you can use it like this:

#[derive(AnchorSerialize, AnchorDeserialize)]
pub enum Grade {
    Pass { value: u64 },
    Fail { value: u64, next_attempt: MyDate },
}