When two pointers point to the same place they alias each other (it's alias as in two names for the same thing, but it's a verb as well as a noun)
Rust's &mut borrow is like a pointer guaranteed to be non-null but also guaranteed to never point to memory that can be accessed by another borrow. Or in other words, &mut can't be aliased by other borrows. If you ever try to alias a &mut borrow, the program won't compile.
C's restrict is kind of similar, but it's far less used than &mut. That's because if you violate aliasing restrictions of restrict, it won't generate a compiler error, but will cause UB!
Anyway in Rust, a &mut has exclusive access to a piece of memory, and the compiler may theoretically make use of this fact in optimizations. However, LLVM isn't yet as good as it could be :( first, I think it doesn't implement yet the real good stuff that GCC has (I found this https://internals.rust-lang.org/t/fyi-ibm-is-working-on-llvm... from 2020 but I don't know the state of it), and worse, what it currently has is very buggy, so sometimes the Rust compiler is forced to disable it :(
Rust's &mut borrow is like a pointer guaranteed to be non-null but also guaranteed to never point to memory that can be accessed by another borrow. Or in other words, &mut can't be aliased by other borrows. If you ever try to alias a &mut borrow, the program won't compile.
C's restrict is kind of similar, but it's far less used than &mut. That's because if you violate aliasing restrictions of restrict, it won't generate a compiler error, but will cause UB!
Anyway in Rust, a &mut has exclusive access to a piece of memory, and the compiler may theoretically make use of this fact in optimizations. However, LLVM isn't yet as good as it could be :( first, I think it doesn't implement yet the real good stuff that GCC has (I found this https://internals.rust-lang.org/t/fyi-ibm-is-working-on-llvm... from 2020 but I don't know the state of it), and worse, what it currently has is very buggy, so sometimes the Rust compiler is forced to disable it :(
So, you have this: https://stackoverflow.com/questions/57259126/why-does-the-ru...