---
title: groups
framework: metal
role: symbol
role_heading: Instance Property
path: metal/mtl4staticlinkingdescriptor/groups
---

# groups

Assigns groups of functions to match call-site attributes in shader code.

## Declaration

```swift
var groups: [String : [MTL4FunctionDescriptor]]? { get set }
```

## Discussion

Discussion Function groups help the compiler reduce the number of candidate functions it needs to evaluate for shader function calls, potentially increasing runtime performance.