我怎样才能改变“_Ctype_int”为“int”进去吗？

Question

I have a slice that I need to change from _Ctype_int to int.

fmt.Printf("Slice Type: %T", slice) //Returns Slice Type: []main._Ctype_int

Do you know of a simple conversion? Thank you!

Here is the code that returns a pointer to array in C++

   #include "camera.hxx"
   #include <iostream>

   Camera::Camera()
   {
   }

   int* Camera::retrieveDataPointerPerBuffer() {
     const int size = 640 * 512;
     static int cameraData[size]; 
     for (int i = 0; i < size; i++) {
     cameraData[i] = i;
      } //Generates dummy 512x640 camera data
      int* pSrc = cameraData;
      return pSrc;
   } //C++ file

This code calls the c++ function in Go.

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

    arraySize := 512 * 640
    slice := (*[1 << 30]C.int)(unsafe.Pointer(pSrc))[:arraySize:arraySize]

    fmt.Printf("
Slice Type: %T
", slice)
 }

 func main() {
     go myCamera()
     time.Sleep(15 * time.Millisecond)
 }

I am using SWIG to wrap the C++ for Go

Answer 1

The size of a C int and a Go int are implementation dependent and they are not necessarily the same.

---

For example, to convert between different memory layouts,

package main

import (
    "fmt"
    "unsafe"
)

import "C"

func main() {
    cInts := []C.int{0, 1, 2}
    fmt.Println(C.sizeof_int, cInts)
    goInts := make([]int, len(cInts))
    for i, ci := range cInts {
        goInts[i] = int(ci)
    }
    fmt.Println(unsafe.Sizeof(int(0)), goInts)
}

Output:

4 [0 1 2]
8 [0 1 2]

---

$ go version
go version devel +0349f29a55 Thu Feb 21 15:14:45 2019 +0000 linux/amd64
$ gcc --version
gcc (Ubuntu 8.2.0-7ubuntu1) 8.2.0
$ g++ --version
g++ (Ubuntu 8.2.0-7ubuntu1) 8.2.0
$