Function sdallocx 

pub unsafe extern "C" fn sdallocx(
    ptr: *mut c_void,
    size: size_t,
    flags: c_int,
)

Deallocates previously-allocated memory region referenced by ptr with size hint.

This makes the space available for future allocations.

Safety

The behavior is undefined if:

• size is not in range [req_size, alloc_size], where req_size is the size requested when performing the allocation, and alloc_size is the allocation size returned by nallocx, sallocx, or xallocx,
• ptr does not match a pointer earlier returned by the memory allocation functions of this crate, or
• ptr is null, or
• the memory region referenced by ptr has been deallocated.