S0030: tuple field is out of bounds

Generated from rellum-diagnostics/src/db.rs.

Explanation

Tuple field indexes are zero-based and must refer to an existing tuple element. Accessing .N past the tuple's last element would read a value that is not part of the tuple.

Common causes

• using .1 on a one-element tuple
• using .2 on a two-element tuple
• counting tuple fields from one instead of zero

Canonical fixes

• use an existing tuple field index

Before:

value = pair.2

After:

value = pair.1

• add the missing tuple element if the shape is wrong

Before:

pair = (left, right)
value = pair.2

After:

triple = (left, middle, right)
value = triple.2

Code example

value = pair.2

Links

• RellC diagnostic overview