cgo中向C部分函数传入go的slice

注意事项：

传入C函数中的slice需要以&array[0]的形式进行，而不能单纯使用&array，因为go中的slice数据结构不仅仅具有首地址。

类型对应表

type	C	go
char	C.char	byte
signed	C.schar	int8
unsigned char	C.uchar	uint8
short int	C.short	int16
short unsigned int	C.ushort	uint16
int	C.int	int
unsigned int	C.uint	uint32
long int	C.long	int32/int64
long unsigned int	C.ulong	uint32/uint64
long long int	C.longlong	int64
long long unsigned int	C.ulonglong	uint64
float	C.float	float32
double	C.double	float64
wchar_t	C.wchar_t
void *	unsafe.Pointer

例子

package main

/*
struct test_t{
	int a;
};

void setInt(void *t){
	unsigned long *arr = (unsigned long *)t;
	for(int i=0;i<10;i++){
		arr[i] = i;
	}
}

void setTest(void *t){
	struct test_t *m = (struct test_t *)t;
	m->a = 10;
}
*/
// #cgo 386 CFLAGS: -DX86=1
import "C"
import (
	"fmt"
	"unsafe"
)

type test struct {
	a int
}

func main() {
	arr := make([]C.ulong, 10)
	t := test{}
	C.setInt(unsafe.Pointer(&arr[0]))
	C.setTest(unsafe.Pointer(&t))
	fmt.Println(arr)
	fmt.Println(t)
}