# `GSLayer index(of:)`

*Instance Method*

The index of a guide, or `nil` when the guide is not in the layer.

## Declaration

```swift
func index(of guide: GSGuide) -> Int?
```

## See Also

### Guides

- [`GSLayer.guides`](/Core/GlyphsCore/GSLayer/guides) — Layer-local guides.
- [`GSLayer countOfGuides`](/Core/GlyphsCore/GSLayer/countOfGuides) — The number of layer-local guides.
- [`GSLayer objectInGuidesAtIndex:`](/Core/GlyphsCore/GSLayer/objectInGuidesAtIndex:) — The guide at an index.
- [`GSLayer addGuide:`](/Core/GlyphsCore/GSLayer/addGuide:) — Adds a guide.
- [`GSLayer insertObject:inGuidesAtIndex:`](/Core/GlyphsCore/GSLayer/insertObject:inGuidesAtIndex:) — Inserts a guide at an index.
- [`GSLayer removeObjectFromGuides:`](/Core/GlyphsCore/GSLayer/removeObjectFromGuides:) — Removes a guide.
- [`GSLayer removeObjectFromGuidesAtIndex:`](/Core/GlyphsCore/GSLayer/removeObjectFromGuidesAtIndex:) — Removes the guide at an index.