Function nstd_sys::shared_ptr::nstd_shared_ptr_owners

#[no_mangle]
pub extern "C" fn nstd_shared_ptr_owners(
    shared_ptr: &NSTDSharedPtr<'_>
) -> NSTDUInt

Available on crate feature shared_ptr only.

Returns the number of pointers that share shared_ptr’s data.

Parameters:

• const NSTDSharedPtr *shared_ptr - An instance of a shared pointer.

Returns

NSTDUInt owners - The number of pointers that share shared_ptr’s data.

Example

use core::ptr::addr_of;
use nstd_sys::{
    alloc::NSTD_ALLOCATOR,
    shared_ptr::{
        nstd_shared_ptr_get, nstd_shared_ptr_new, nstd_shared_ptr_owners, nstd_shared_ptr_share,
    },
};

const SIZE: usize = core::mem::size_of::<i128>();

unsafe {
    let v = i128::MIN;
    let share;
    {
        let addr = addr_of!(v).cast();
        let shared_ptr = nstd_shared_ptr_new(&NSTD_ALLOCATOR, SIZE, addr).unwrap();
        assert!(nstd_shared_ptr_owners(&shared_ptr) == 1);

        share = nstd_shared_ptr_share(&shared_ptr);
        assert!(nstd_shared_ptr_owners(&shared_ptr) == 2);

        let temp = nstd_shared_ptr_share(&shared_ptr);
        assert!(nstd_shared_ptr_owners(&temp) == 3);
    }
    assert!(nstd_shared_ptr_owners(&share) == 1);
    assert!(*nstd_shared_ptr_get(&share).cast::<i128>() == v);
}