從Swift調用C++ - 什麼是std :: vector <T>

Question

的等價物我正在通過橋接標頭後面的SwiftArchitect's example從Swift調用C++函數。對於C++函數簽名是這樣的：

long GrabberInitializeAndProcess(
    unsigned char* pbInPixels, 
    int inStride, 
    unsigned char* pbOutPixels, 
    int outStride, 
    int width, 
    int height, 
    Point mqTopLeft, 
    Size mqSize, 
    std::vector<PolylineElement> * pForegroundMarks, 
    std::vector<PolylineElement> * pBackgroundMarks, 
    void* pGrabberState); 

（注：Point，Size，並且PolylineElement是本地C++結構。）我在我的Objective-C++包裝使用std::vector<T>什麼簽名？

Answer 1

您正在使用vector作爲指針。當你需要在Swift中使用它時非常好。

您可以使用void*代替：

long GrabberInitializeAndProcess(
    unsigned char* pbInPixels, 
    int inStride, 
    unsigned char* pbOutPixels, 
    int outStride, 
    int width, 
    int height, 
    Point mqTopLeft, 
    Size mqSize, 
    void * pForegroundMarks, 
    void * pBackgroundMarks, 
    void* pGrabberState); 

而且在實施執行類型轉換。

或者，如果你需要的類型安全，你可以白：

typedef struct _vectorOfPolylineElement *vectorOfPolylineElementPtr; 

long GrabberInitializeAndProcess(
    unsigned char* pbInPixels, 
    int inStride, 
    unsigned char* pbOutPixels, 
    int outStride, 
    int width, 
    int height, 
    Point mqTopLeft, 
    Size mqSize, 
    vectorOfPolylineElementPtr pForegroundMarks, 
    vectorOfPolylineElementPtr pBackgroundMarks, 
    void* pGrabberState); 

而且在執行：

typedef struct _vectorOfPolylineElement 
{ 
    std::vector<PolylineElement> val; 
} *vectorOfPolylineElementPtr; 

如果你其實並不需要GrabberInitializeAndProcess載體，只是它的元素，你可以使用內存：

long GrabberInitializeAndProcess(
    unsigned char* pbInPixels, 
    int inStride, 
    unsigned char* pbOutPixels, 
    int outStride, 
    int width, 
    int height, 
    Point mqTopLeft, 
    Size mqSize, 
    PolylineElement * pForegroundMarks, 
    size_t foregroundMarksCount, 
    PolylineElement * pBackgroundMarks, 
    size_t backgroundMarksCount, 
    void* pGrabberState);