给定一个UnsafeMutablePointer实例，在deallocate(capacity:)之前调用deinitialize(count:)有什么意义？你不能直接调用deallocate(capacity:)吗？我在阅读文章UnsafeSwift:UsingPointersAndInteractingWithC的“使用类型化指针”部分时看到了这一点在raywenderlich.com.本文包含以下代码，您可以将其添加到Xcode中的新Playground。letcount=2letstride=MemoryLayout.strideletalignment=MemoryLayou

下面的代码会产生这个错误(附加到exporters):fatalerror:UnsafeMutablePointer.deinitializewithnegativecountvarexporters=[AVAssetExportSession]()letexporter=AVAssetExportSession(asset:mainComposition,presetName:AVAssetExportPresetHighestQuality)!exporter.videoComposition=videoCompositionexporter.outputFileType=AVFi

下面的代码会产生这个错误(附加到exporters):fatalerror:UnsafeMutablePointer.deinitializewithnegativecountvarexporters=[AVAssetExportSession]()letexporter=AVAssetExportSession(asset:mainComposition,presetName:AVAssetExportPresetHighestQuality)!exporter.videoComposition=videoCompositionexporter.outputFileType=AVFi