You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: stack.rs
    path of file: ./repos/Project-47/pr47-core/src/vm/al31f
    
    the code of the file until where you have to start completion: use std::ptr::{addr_of_mut, NonNull, slice_from_raw_parts_mut};

use crate::data::Value;

#[cfg(debug_assertions)]
#[derive(Copy, Clone)]
pub struct StackSlice(*mut [Option<Value>]);

#[cfg(debug_assertions)]
impl StackSlice {
    pub unsafe fn set_value(&mut self, idx: usize, value: Value) {
        (*self.0)[idx].replace(value);
    }

    pub unsafe fn get_value(&self, idx: usize) -> Value {
        (*self.0)[idx].unwrap()
    }

    pub unsafe fn get_value_mut_ref(&self, idx: usize) -> *mut Value {
        // create empty, dummy value
        let value: &mut Value = (*self.0)[idx].get_or_insert(Value::new_null());
        value as *mut Value
    }
}

#[cfg(not(debug_assertions))]
#[derive(Copy, Clone)]
pub struct StackSlice(*mut Value);

#[cfg(not(debug_assertions))]
impl StackSlice {
    #[inline(
    
    pub fn trace(&self) {
        eprintln!("[STACK-TRACE] Begin stack tracing");
        eprintln!("[STACK-TRACE] {{");
        for (i, frame) /*: (usize, &FrameInfo)*/ in self.frames.iter().enumerate() {
            eprintln!("[STACK-TRACE]     <frame {}: size = {}, ret_addr = {}, ret_val_locs = {:?}>",
                      i,
                      frame.frame_end - frame.frame_start,
                      frame.ret_addr,
                      unsafe { frame.ret_value_locs.as_ref() });
            eprintln!("[STACK-TRACE]     [");
            #[cfg(debug_assertions)]
            for i /*: usize*/ in frame.frame_start..frame.frame_end {
                if let Some(value /*: &Value*/) = &self.values[i] {
                    eprintln!("[STACK-TRACE]         [{}] = {:?}", i - frame.frame_start, value);
                } else {
                    eprintln!("[STACK-TRACE]         [{}] = UNINIT", i - frame.frame_start);
                }
            }
            #[cfg(not(debug_assertions))]
            for i /*: usize*/ in frame.frame_start..frame.frame_end {
                let value: &Value = &self.values[i];
                eprintln!("[STACK-TRACE]         [{}] = {:?}", i - frame.frame_start, value);
            }
            eprintln!("[STACK-TRACE]     ]");
        }
        eprintln!("[STACK-TRACE] }}");
        eprintln!("[STACK-TRACE] End stack tracing");
    }