# XO0537: retired: a by value receiver read before an argument that changes it

xo vet used to report `x.m(x.n(..))` where m takes x by value and n is a `var` method of x, because the call read x before n ran. Decision 0326 made the receiver read after the arguments (as a `var` receiver always was, decision 0142), so the check was removed. The code stays reserved. See the gotcha receiver-read-before-args.

## Example

```xo
fn size_of(var t: Table, v: Int) -> Int {
  t.size(t.add(v))
}
```

## Fix

```xo
// no change needed: size sees the item add pushed
```

Run `xo explain XO0537` for this text in a terminal, or see
[section 10.6 of the specification](../../spec/core/#106-diagnostic-codes).