Rust: 3 core concept

90% "susahnya" Rust ada di 3 konsep ini

Ownership

Every value is 'owned' by a single variable, struct, vector, etc at a time
Reassigning the value to another variable, passing it to a function, putting it into a vector, etc, MOVES the value. The old variable can't be used anymore

You can create many read-only references to a value that exist at the same time
You can't move a value while a ref to the value exist
You can make writable (mutable) reference to a value ONLY IF there are no read-only references currently in use. One mutable ref to a value can exist at a time
You can't mutate a value through the owner when any ref (mutable or immutable) to the value exist
Some types of values are COPIED instead of move (numbers, bools, chars, arrays/tuple with copyable elements)

When a variable goes out of scope, the value owned by it is dropped (cleaned up in memory)
Values can't be dropped if there are still active references to it
References to a value can't outlive the value the refer to