---
title: "initializeMemory(as:from:count:)"
framework: swift
role: symbol
role_heading: Instance Method
path: "swift/unsafemutablerawpointer/initializememory(as:from:count:)"
---

# initializeMemory(as:from:count:)

Initializes the memory referenced by this pointer with the values starting at the given pointer, binds the memory to the values’ type, and returns a typed pointer to the initialized memory.

## Declaration

```swift
@discardableResult func initializeMemory<T>(as type: T.Type, from source: UnsafePointer<T>, count: Int) -> UnsafeMutablePointer<T>
```

## Parameters

- `type`: The type to bind this memory to.
- `source`: A pointer to the values to copy. The memory in the region source..<(source + count) must be initialized to type T and must not overlap the destination region.
- `count`: The number of copies of value to copy into memory. count must not be negative.

## Return Value

Return Value A typed pointer to the memory referenced by this raw pointer.

## Discussion

Discussion The memory referenced by this pointer must be uninitialized or initialized to a trivial type, and must be properly aligned for accessing T. The following example allocates enough raw memory to hold four instances of Int8, and then uses the initializeMemory(as:from:count:) method to initialize the allocated memory. let count = 4 let bytesPointer = UnsafeMutableRawPointer.allocate(         byteCount: count * MemoryLayout<Int8>.stride,         alignment: MemoryLayout<Int8>.alignment) let values: [Int8] = [1, 2, 3, 4] let int8Pointer = values.withUnsafeBufferPointer { buffer in     return bytesPointer.initializeMemory(as: Int8.self,               from: buffer.baseAddress!,               count: buffer.count) } // int8Pointer.pointee == 1 // (int8Pointer + 3).pointee == 4

// After using 'int8Pointer': int8Pointer.deallocate() After calling this method on a raw pointer p, the region starting at p and continuing up to p + count * MemoryLayout<T>.stride is bound to type T and initialized. If T is a nontrivial type, you must eventually deinitialize or move from the values in this region to avoid leaks. The instances in the region source..<(source + count) are unaffected.