---
title: "CFBitVectorCreate(_:_:_:)"
framework: corefoundation
role: symbol
role_heading: Function
path: "corefoundation/cfbitvectorcreate(_:_:_:)"
---

# CFBitVectorCreate(_:_:_:)

Creates an immutable bit vector from a block of memory.

## Declaration

```swift
func CFBitVectorCreate(_ allocator: CFAllocator!, _ bytes: UnsafePointer<UInt8>!, _ numBits: CFIndex) -> CFBitVector!
```

## Parameters

- `allocator`: The allocator to use to allocate memory for the new bit vector. Pass NULL or kCFAllocatorDefault to use the current default allocator.
- `bytes`: A pointer to the bit values to store in the new bit vector. The values are copied into the bit vector’s own memory. The bit indices are numbered left-to-right with 0 being the left-most, or most-significant, bit in the byte stream.
- `numBits`: The number of bits in the bit vector.

## Return Value

Return Value A new bit vector. Ownership follows the The Create Rule.

## See Also

### Creating a Bit Vector

- [CFBitVectorCreateCopy(_:_:)](corefoundation/cfbitvectorcreatecopy(_:_:).md)