Handling Generic Types with Specific Fields in Move Functions

[0xAnto]

Discord user ID

0xanto_

Describe your question in detail.

I'm trying to write a generic function in Move that works with multiple structs having a common field. Here's the example:

struct TypeA has store, copy, drop {
    id: u128,
    value: u64,
}

struct TypeB has store, copy, drop {
    id: u128,
    value: u64,
}

public fun find_item_index<T>(
    items: &vector<T>, target_id: u128
): (bool, u64) {
    let length = vector::length(items);
    let found = false;
    let index = 0;
    let i = 0;
    while (i < length) {
        // Error occurs here
        if (items.borrow(i).id == target_id) {
            found = true;
            index = i;
            break;
        };
        i = i + 1;
    };
    (found, index)
}

The issue I'm facing is that the compiler gives an error: "Unresolved field: id" when trying to access the id field of items.borrow(i).

How can I make the generic type T in find_item_index ensure that it has an id field? Is there a way to define constraints for generic types in Move to solve this issue?

What error, if any, are you getting?

"Unresolved field: id" when trying to access the id field.

What have you tried or looked at? Or how can we reproduce the error?

No response

Which operating system are you using?

macOS

Which SDK or tool are you using? (if any)

Aptos CLI

Describe your environment or tooling in detail

aptos 5.1.0