---
title: "initialize(from:count:)"
framework: swift
role: symbol
role_heading: Instance Method
path: "swift/unsafemutablepointer/initialize(from:count:)"
---

# initialize(from:count:)

Initializes the memory referenced by this pointer with the values starting at the given pointer.

## Declaration

```swift
func initialize(from source: UnsafePointer<Pointee>, count: Int)
```

## Parameters

- `source`: A pointer to the values to copy. The memory region source..<(source + count) must be initialized. The memory regions referenced by source and this pointer must not overlap.
- `count`: The number of instances to move from source to this pointer’s memory. count must not be negative.

## Discussion

Discussion The region of memory starting at this pointer and covering count instances of the pointer’s Pointee type must be uninitialized or Pointee must be a trivial type. After calling initialize(from:count:), the region is initialized. note: The source and destination memory regions must not overlap.