# select(_:_:) Adds a tensor-scalar select operation to the current graph. ``` func select(_ valueIfTrue: BNNSGraph.Builder.Tensor, _ valueIfFalse: any BNNSGraph.Builder.OperationParameter) -> BNNSGraph.Builder.Tensor where U : BNNSScalar ``` ## Parameters `valueIfTrue` The values that the operation returns when the corresponding value in `self` is `true`. `valueIfFalse` The value that the operation returns when the corresponding value in `self` is `false`. ## Discussion For example, the following code returns the `valueIfTrue` elements when the corresponding elements in `z` are `true` and `Float.infinity` when the corresponding elements in `z` are `false`: ``` let ctx = try BNNSGraph.makeContext { builder in let z = builder.argument(dataType: Bool.self, shape: [8]) let x = builder.argument(dataType: Float.self, shape: [8]) let masked = z.select(x, Float.infinity) return [ masked ] } let z = BNNSTensor.allocate(initializingFrom: [true, true, false, false, true, true, false, false], shape: [8], stride: [1]) let x = BNNSTensor.allocate(initializingFrom: [1, 2, 3, 4, 5, 6, 7, 8] as [Float], shape: [8], stride: [1]) let tensor_scalar = BNNSTensor.allocateUninitialized(scalarType: Float.self, shape: [8], stride: [1]) var args = [tensor_tensor, tensor_scalar, scalar_tensor, z, x] try ctx.executeFunction(arguments: &args) // Prints "[1.0, 2.0, Float.infinity, Float.infinity, 5.0, 6.0, Float.infinity, Float.infinity]". print(tensor_scalar.makeArray(of: Float.self)) ``` --- 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)