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CFShow
Prints a description of a Core Foundation object to stderr.
Declaration
SWIFT
func CFShow(_ obj: AnyObject!)
OBJECTIVE-C
void CFShow ( CFTypeRef obj );
Parameters
obj
A Core Foundation object derived from CFType. If obj is not a Core Foundation object, an assertion is raised.
Discussion
The output is printed to the standard I/O standard error (stderr).
This function is useful as a debugging aid for Core Foundation objects. Because these objects are based on opaque types, it is difficult to examine their contents directly. However, the opaque types implement description function callbacks that return descriptions of their objects. This function invokes these callbacks.
Special Considerations
You can use CFShow in one of two general ways. If your debugger supports function calls (such as gdb does), call CFShow in the debugger:
(gdb) call (void) CFShow(string)
Hello World
You can also incorporate calls to CFShow in a test version of your code to print out "snapshots" of Core Foundation objects to the console.
Import Statement
import CoreFoundation
Availability
Available in iOS 2.0 and later.
