This will have false positives.

```rust
let x: int = "//"; //~ ERROR mismatched types
```

This code will ignore that.

I don't think there's any quick fix. You could try to test for strings, and for multi-line comments, etc, but this could always be a multi-line expression where the string started on a previous line.

```rust
let example_format = "
    some error here; //~ ERROR error message
";
```