create\_shared\_buffer - create a shareable memory buffer
## Synopsis
```**c++
#include <SharedBuffer.h>
int create_shared_buffer(int size, void** buffer);
```
## Description
Creates a new memory region that can be shared with other processes. The region is only accessible to the creating process by default.
## Return value
If a region is successfully created, `create_shared_buffer()` stores a pointer to the memory in `buffer` and returns a buffer ID. Otherwise, it returns -1 and sets `errno` to describe the error.
