# libtmux::is_pane_id

- **Module:** libtmux
- **Package:** libtmux-cxx
- **Language:** C++
- **Kind:** function
- **Source:** https://github.com/libtmux/libtmux-cxx/blob/85e8bd603a322dc32bb8b9aeb1a72bcf36945f1d/include/libtmux/target.hpp#L38
- **Page:** https://libtmux.org/reference/cxx/libtmux-is_pane_id/

```
libtmux::is_pane_id(value: std::string_view) -> bool
```

Whether a value is written as an id, which is what decides that it needs no separator validation below — not whether tmux would resolve it.

`x` is an id by this test and no pane by tmux's, and both are right: it carries no separator, so composing it can only produce the caller's own mistake back.