# setConstantValues(_:type:range:) Sets values for a group of function constants within a specific index range. ``` func setConstantValues(_ values: UnsafeRawPointer, type: MTLDataType, range: Range) ``` ## Parameters `values` A pointer to the constant values. `type` The data type of the function constants. `range` The range of the function constant indices. ## Discussion Declare multiple function constants in Metal Shading Language (MSL). ```metal constant bool a [[ function_constant(0) ]]; constant bool b [[ function_constant(1) ]]; constant bool c [[ function_constant(2) ]]; ``` Set their values by assigning an index range of an array. ```swift let abc = [true, true, true] let constantValues = MTLFunctionConstantValues() constantValues.setConstantValues(abc, type: .bool, with: NSMakeRange(0, 3)) ``` --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)