Intermediate
Rust
Q53 / 100
What is the purpose of PhantomData<T>?
Correct! Well done.
Incorrect.
The correct answer is B) A zero-sized type used to make the type system aware of an unused generic parameter for lifetime or type variance purposes
B
Correct Answer
A zero-sized type used to make the type system aware of an unused generic parameter for lifetime or type variance purposes
Explanation
struct Iter<'a, T> { ptr: *const T, _phantom: PhantomData<&'a T> } tells the compiler the Iter borrows T with lifetime 'a, enabling proper variance.
Progress
53/100