withUnsafeBytes(_:)
Calls the given closure with a pointer to the underlying bytes of the viewed contiguous storage.
Declaration
func withUnsafeBytes<E, Result>(_ body: (UnsafeRawBufferPointer) throws(E) -> Result) throws(E) -> Result where E : Error, Result : ~CopyableParameters
- body:
A closure with an
UnsafeRawBufferPointerparameter that points to the viewed contiguous storage. Ifbodyhas a return value, that value is also used as the return value for thewithUnsafeBytes(_:)method. The closure’s parameter is valid only for the duration of its execution.
Return Value
The return value of the body closure parameter.
Discussion
The buffer pointer passed as an argument to body is valid only during the execution of withUnsafeBytes(_:). Do not store or return the pointer for later use.
Note: For an empty Span, the closure always receives a nil pointer.