使用SWIG进行C ++编程：如何将C ++指针传递给Go？ [重复]

Question

This question already has an answer here:

• How to pass pointer to slice to C function in go 1 answer
• cgo: How to pass struct array from c to go 1 answer
• Export function that returns array of doubles 1 answer
• casting a cgo array into a slice 1 answer
• Access C array of type const char * from Go 1 answer

See code below and I will explain

int* Camera::retrieveDataPointerPerBuffer() {
    int cameraData [10] = {1,2,3,4,5,6,7,8,9,10};
    int* pSrc = cameraData;
    return cameraData; 
} //camera.cpp

The code above has int pointer pSrc pointing to array and then returned. This is a function in C++. Next, I am using SWIG to essentially wrap this C++ function, so that I can call it in Go. The following code demonstrates the function being called in Go.

func myCamera() {
    cam := camera.NewCamera()
    pSrc := cam.RetrieveDataPointerPerBuffer()

    for i := 0; i < 10; i++ {
        fmt.Println("%d", pSrc)
    }
} //main.go

Note: I know that I cannot iterate pointers in Go. But is there any way?

Output: 0

Problems: How do you access the arrays elements via pointer from C++ to Go? Additional Information: This is a simplified version of a larger project I am working on. I must return this pointer, I cannot return a vector.

Let me know if you need me to clarify anything for you.

</div>

Answer 1

@JimB Thanks for all of your resources. I figured it out and this seems to do the trick.

int* Camera::retrieveDataPointerPerBuffer() {
   int cameraData [10] = {1,2,3,4,5,6,7,8,9,10};
   int* pSrc = cameraData;
   return cameraData; 
} //camera.cpp

Below contains the changes that I made

func myCamera() { //For Goroutine
   cam := camera.NewCamera()
   pSrc := cam.RetrieveDataPointerPerBuffer()

   arraySize := 10
   slice := (*[1 << 30]C.int)(unsafe.Pointer(pSrc))[:arraySize:arraySize]

   fmt.Println(slice)
}

Output: [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]

Follow Up Question: Would anyone mind explaining this line of code?

slice := (*[1 << 30]C.int)(unsafe.Pointer(pSrc))[:arraySize:arraySize]