-fsanitize-bounds uses a runtime address sanitizer, surely? The program compiles fine. In a (strongly) dependently typed language, something like the following would refuse to typecheck:

  int foo(int i) {
      int bar[4] = { 1, 2, 3, 4 };
      return bar[i]
  }

The type checker would demand a proof that i is in bounds, for example

  int foo(int i) {
      int bar[4] = { 1, 2, 3, 4 };
      if i < 4
          return bar[i]
      else 
          return 0
  }

In languages with an Option type this could of course be written without dependent types in a way that's still correct by construction, for example Rust:

  fn foo(i: 32) -> i32 {
      let bar = [1, 2, 3, 4];
      bar.get(i)       // returns Option<i32>, not a raw i32
         .unwrap_or(0) // provide a default, now we always have an i32
  }

But ultimately, memory safety here is only guaranteed by the library, not by the type system.