how to put struct to queue

[chansonZ]

Can anyone help?

typedef struct {
    int a;
    char b[32];
} UserData;

compile error when:

constexpr unsigned CAPACITY = 1024;
AtomicQueue<UserData, CAPACITY> q; 

[max0x7ba]

When you report problems, you should provide a complete reproducible example with the error message, so that no guesswork or undue effort is required to help you.

---

Your code doesn't compile because you use queue template AtomicQueue designed for atomic elements, whereas UserData isn't one.

Queue template AtomicQueue2, on the other hand, is designed for non-atomic elements and that is what you should use:

AtomicQueue2<UserData, CAPACITY> q;

You should always read documentation before using something or asking questions. 15 minutes spent on reading documentation saves you endless hours of debugging.