Rollup merge of #30760 - jonastepe:nomicon_vec_insert_remove_len, r=apasel422

len needs to be prefixed by self for this to work. That is something which trips me up all the time. It's reassuring to see that happening to seasoned Rust programmers.

Author: steveklabnik

src/doc/nomicon/vec-insert-remove.md

@@ -24,7 +24,7 @@ pub fn insert(&mut self, index: usize, elem: T) {
             // ptr::copy(src, dest, len): "copy from source to dest len elems"
             ptr::copy(self.ptr.offset(index as isize),
                       self.ptr.offset(index as isize + 1),
-                      len - index);
+                      self.len - index);
         }
         ptr::write(self.ptr.offset(index as isize), elem);
         self.len += 1;
@@ -44,7 +44,7 @@ pub fn remove(&mut self, index: usize) -> T {
         let result = ptr::read(self.ptr.offset(index as isize));
         ptr::copy(self.ptr.offset(index as isize + 1),
                   self.ptr.offset(index as isize),
-                  len - index);
+                  self.len - index);
         result
     }
 }