Function SecTransformPushbackAttribute 

pub unsafe extern "C-unwind" fn SecTransformPushbackAttribute(
    ref: SecTransformImplementationRef,
    attribute: &SecTransformStringOrAttribute,
    value: &CFType,
) -> Option<CFRetained<CFType>>

👎Deprecated: SecTransform is no longer supported

Available on crate feature SecCustomTransform only.

Allows for putting a single value back for a specific attribute. This will stop the flow of data into the specified attribute until any attribute is changed for the transform instance bound to the ref parameter.

Parameter ref: A SecTransformImplementationRef that is bound to an instance of a custom transform.

Parameter attribute: The name or the attribute handle of the attribute whose value is to be pushed back.

Parameter value: The value being pushed back.

Returns: A CFErrorRef if an error occured , NULL otherwise.

Safety

• ref must be a valid pointer.
• attribute should be of the correct type.
• value should be of the correct type.