If you have indicated that Xcodeshould do so, Xcode precompiles the prefix header when you buildthe target. Xcode then includes that precompiled header file foreach of the target's source files. The contents of the prefixheader are compiled only once, resulting in faster compilation ofeach source file. Furthermore, subsequent builds of the target canuse that same precompiled header, provided that nothing in theprefix header or any of the files on which it depends has changed.Each target can have only one prefix header.If you have indicated that Xcodeshould do so, Xcod
