Have macro 'return' a value

Question

I\'m using a macro and I think it works fine -

#define CStrNullLastNL(str) {char* nl=strrchr(str,\'\\n\'); if(nl){*nl=0;}}

So it works to zero out the last

Answer 1

If you don't have a strict requirement to use only macro, you can do something like this (real life example):

#define Q_XCB_SEND_EVENT_ALIGNED(T) \
    q_xcb_send_event_aligned()

template inline
T q_xcb_send_event_aligned()
{
    union {
        T event;
        char padding[32];
    } event;

    memset(&event, 0, sizeof(event));
    return event.event;
}

And then use it in your code like this:

auto event = Q_XCB_SEND_EVENT_ALIGNED(xcb_unmap_notify_event_t);