# Objective
- Rebase of #3159.
- Fixes https://github.com/bevyengine/bevy/issues/3156
- add #[inline] to single related functions so that they matches with other function defs
## Solution
* added functions to QueryState
* get_single_unchecked_manual
* get_single_unchecked
* get_single
* get_single_mut
* single
* single_mut
* make Query::get_single use QueryState::get_single_unchecked_manual
* added #[inline]
---
## Changelog
### Added
Functions `QueryState::single`, `QueryState::get_single`, `QueryState::single_mut`, `QueryState::get_single_mut`, `QueryState::get_single_unchecked`, `QueryState::get_single_unchecked_manual`.
### Changed
`QuerySingleError` is now in the `state` module.
## Migration Guide
Change `query::QuerySingleError` to `state::QuerySingleError`
Co-authored-by: 2ne1ugly <chattermin@gmail.com>
Co-authored-by: 2ne1ugly <47616772+2ne1ugly@users.noreply.github.com>