Make Tensor data accessors non-throwing.

Differential Revision: D79381680

Pull Request resolved: #13087

Author: shoumikhin

docs/source/using-executorch-ios.md

@@ -246,7 +246,7 @@ let inputTensor = Tensor<Float>(&imageBuffer, shape: [1, 3, 224, 224])
 let outputTensor: Tensor<Float> = try module.forward(inputTensor)[0].tensor()!
 
 // Copy the tensor data into logits array for easier access.
-let logits = try outputTensor.scalars()
+let logits = outputTensor.scalars()
 
 // Use logits...
 ```
@@ -444,11 +444,11 @@ Swift:
 let tensor = Tensor<Float>([1.0, 2.0, 3.0, 4.0], shape: [2, 2])
 
 // Get data copy as a Swift array.
-let scalars = try tensor.scalars()
+let scalars = tensor.scalars()
 print("All scalars: \(scalars)") // [1.0, 2.0, 3.0, 4.0]
 
 // Access data via a buffer pointer.
-try tensor.withUnsafeBytes { buffer in
+tensor.withUnsafeBytes { buffer in
   print("First float element: \(buffer.first ?? 0.0)")
 }
 
@@ -482,7 +482,7 @@ Swift:
 let tensor = Tensor<Float>([1.0, 2.0, 3.0, 4.0], shape: [2, 2])
 
 // Modify the tensor's data in place.
-try tensor.withUnsafeMutableBytes { buffer in
+tensor.withUnsafeMutableBytes { buffer in
   buffer[1] = 200.0
 }
 // tensor's data is now [1.0, 200.0, 3.0, 4.0]

extension/apple/ExecuTorch/Exported/ExecuTorch+Tensor.swift

@@ -770,35 +770,29 @@ public final class Tensor<T: Scalar>: Equatable {
   /// - Parameter body: A closure that receives an `UnsafeBufferPointer<T>` bound to the tensor’s data.
   /// - Returns: The value returned by `body`.
   /// - Throws: Any error thrown by `body`.
-  public func withUnsafeBytes<R>(_ body: (UnsafeBufferPointer<T>) throws -> R) throws -> R {
-    var result: Result<R, Error>?
-    anyTensor.bytes { pointer, count, _ in
-      result = Result { try body(
-        UnsafeBufferPointer(
-          start: pointer.assumingMemoryBound(to: T.self),
-          count: count
-        )
-      ) }
+  public func withUnsafeBytes<R>(_ body: (UnsafeBufferPointer<T>) throws -> R) rethrows -> R {
+    try withoutActuallyEscaping(body) { body in
+      var result: Result<R, Error>?
+      anyTensor.bytes { pointer, count, _ in
+        result = Result { try body(UnsafeBufferPointer(start: pointer.assumingMemoryBound(to: T.self), count: count)) }
+      }
+      return try result!.get()
     }
-    return try result!.get()
   }
 
   /// Calls the closure with a typed, mutable buffer pointer over the tensor’s elements.
   ///
   /// - Parameter body: A closure that receives an `UnsafeMutableBufferPointer<T>` bound to the tensor’s data.
   /// - Returns: The value returned by `body`.
   /// - Throws: Any error thrown by `body`.
-  public func withUnsafeMutableBytes<R>(_ body: (UnsafeMutableBufferPointer<T>) throws -> R) throws -> R {
-    var result: Result<R, Error>?
-    anyTensor.mutableBytes { pointer, count, _ in
-      result = Result { try body(
-        UnsafeMutableBufferPointer(
-          start: pointer.assumingMemoryBound(to: T.self),
-          count: count
-        )
-      ) }
+  public func withUnsafeMutableBytes<R>(_ body: (UnsafeMutableBufferPointer<T>) throws -> R) rethrows -> R {
+    try withoutActuallyEscaping(body) { body in
+      var result: Result<R, Error>?
+      anyTensor.mutableBytes { pointer, count, _ in
+        result = Result { try body(UnsafeMutableBufferPointer(start: pointer.assumingMemoryBound(to: T.self), count: count)) }
+      }
+      return try result!.get()
     }
-    return try result!.get()
   }
 
   /// Resizes the tensor to a new shape.
@@ -830,9 +824,8 @@ public extension Tensor {
   /// Returns the tensor's elements as an array of scalars.
   ///
   /// - Returns: An array of scalars of type `T`.
-  /// - Throws: An error if the underlying data cannot be accessed.
-  func scalars() throws -> [T] {
-    try withUnsafeBytes { Array($0) }
+  func scalars() -> [T] {
+    withUnsafeBytes { Array($0) }
   }
 }