update(fromContentsOf:)
Updates the buffer slice’s initialized memory with every element of the source.
Declaration
func update<Element>(fromContentsOf source: some Collection) -> Slice<Base>.Index where Base == UnsafeMutableBufferPointer<Element>Parameters
- source:
A collection of elements to be used to update the buffer’s contents.
Return Value
An index one past the index of the last element updated.
Discussion
Prior to calling the update(fromContentsOf:) method on a buffer slice, the first source.count elements of the referenced memory must be initialized, or the Element type must be a trivial type. The buffer slice must reference enough initialized memory to accommodate source.count elements.
The returned index is one past the index of the last element updated. If source contains no elements, the returned index is the buffer slice’s startIndex. If source contains as many elements as the buffer slice can hold, the returned index is the buffer slice’s endIndex.