Function jemallocator::usable_size

pub unsafe fn usable_size<T>(ptr: *const T) -> usize

Return the usable size of the allocation pointed to by ptr.

The return value may be larger than the size that was requested during allocation. This function is not a mechanism for in-place realloc(); rather it is provided solely as a tool for introspection purposes. Any discrepancy between the requested allocation size and the size reported by this function should not be depended on, since such behavior is entirely implementation-dependent.

Unsafety

ptr must have been allocated by Jemalloc and must not have been freed yet.