Contents

initializeMemory(as:repeating:count:)

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

Declaration

@discardableResult func initializeMemory<T>(as type: T.Type, repeating repeatedValue: T, count: Int) -> UnsafeMutablePointer<T>

Parameters

  • type:

    The type to bind this memory to.

  • repeatedValue:

    The instance to copy into memory.

  • count:

    The number of copies of value to copy into memory. count must not be negative.

Return Value

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

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:repeating:count:) method to initialize the allocated memory.

let count = 4
let bytesPointer = UnsafeMutableRawPointer.allocate(
        byteCount: count * MemoryLayout<Int8>.stride,
        alignment: MemoryLayout<Int8>.alignment)
let int8Pointer = bytesPointer.initializeMemory(
        as: Int8.self, repeating: 0, count: count)

// After using 'int8Pointer':
int8Pointer.deallocate()

After calling this method on a raw pointer p, the region starting at self 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.