Calls the given closure with a mutable pointer to the given argument.
SDK
- Xcode 8.0+
Framework
- Swift Standard Library
Declaration
func withUnsafeMutablePointer<T, Result>(to value: inout T, _ body: (UnsafeParameters
valueAn instance to temporarily use via pointer. Note that the
inoutexclusivity rules mean that, like any otherinoutargument,valuecannot be directly accessed by other code for the duration ofbody. Access must only occur through the pointer argument tobodyuntilbodyreturns.bodyA closure that takes a mutable pointer to
valueas its sole argument. If the closure has a return value, that value is also used as the return value of thewithfunction. The pointer argument is valid only for the duration of the function’s execution.Unsafe Mutable Pointer(to: _:)
Return Value
The return value, if any, of the body closure.
Discussion
The with function is useful for calling Objective-C APIs that take in/out parameters (and default-constructible out parameters) by pointer.
The pointer argument to body is valid only during the execution of with. Do not store or return the pointer for later use.