Memory Management
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Python Memory Management
- The Python Memory Model
dictis a hash map
Rust Memory Management
Visualizing memory layout of Rust’s data types
Dynamically sized type (DST) in rust
- Reason
- they are DST cuz by looking at the type [T], its size is indeed not known at compile time. Sometimes we type
let b: [u8] = a[0..2]. It seems that we know the size of slice, which is 2, but it is evaluated at run time. The type fora[0..2],a[0..5],a[n..m]is also [u8] at compile time.
- they are DST cuz by looking at the type [T], its size is indeed not known at compile time. Sometimes we type
- Solution
- However, we can turn it into reference type &[T], &str, &dyn Trait, then its size is now known at compile time, which is a fat pointer storing a pointer and a length (not for the case of trait object).
- Vector is not DST
- size of vector is known at compile time, which is a fat pointer storing a pointer, capacity, and length.
- capacity is its max length allocated
- length is the current number of the elements