# LibTmux::FilterExpr#to_proc

- **Module:** LibTmux
- **Package:** libtmux
- **Language:** Ruby
- **Kind:** method
- **Source:** https://github.com/libtmux/libtmux-ruby/blob/c8b839595d5a30e271e3f9be0d0fe811ddb11b7e/gems/libtmux/lib/libtmux/criteria.rb#L101
- **Page:** https://libtmux.org/en/ruby/v0.1.0/reference/libtmux-filterexpr-to_proc/

```
def to_proc: () -> ^(untyped) -> bool
```

Behavior: Criteria.

Behavior contract: Criteria.