pub fn pop(&mut self) -> Option<*mut usize> {
        let value = self.peek()?;
        self.head = unsafe { *value as *mut usize };
        Some(value)
    }
/// Removes and returns the first item in the list, if any.
Removes and returns the first item in the list, if any.
Removes and returns the first item in the list if any .
pub fn pop(&mut self) -> Option<*mut usize> {
        let value = self.peek()?;
        self.head = unsafe { *value as *mut usize };
        Some(value)
    }
pub fn pop ( & mut self ) -> Option < * mut usize > { let value = self . peek ( ) ? ; self . head = unsafe { * value as * mut usize } ; Some ( value ) }
Removes and returns the first item in the list, if any.
Removes and returns the first item in the list if any .
&mut self