From 2f4032b64a8a88846100b5d4e4aafb35d1551b74 Mon Sep 17 00:00:00 2001
From: raj_mathe <raj.dahya@math.uni-leipzig.de>
Date: Fri, 8 Apr 2022 17:07:03 +0200
Subject: [PATCH] master > master: code-rust - minor

---
 code/rust/src/core/utils.rs | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/code/rust/src/core/utils.rs b/code/rust/src/core/utils.rs
index 9cc015a..8ce35d5 100644
--- a/code/rust/src/core/utils.rs
+++ b/code/rust/src/core/utils.rs
@@ -31,7 +31,7 @@ pub fn min<T>(x: T, y: T) -> T
 // METHODS Vectors
 // ----------------------------------------------------------------
 
-pub fn restrict<T>(x: &mut Vec<T>, i: usize, j: usize) -> Vec<T>
+pub fn restrict<T>(x: &Vec<T>, i: usize, j: usize) -> Vec<T>
     where T: Clone
 {
     return x[i..j].iter()
@@ -39,17 +39,23 @@ pub fn restrict<T>(x: &mut Vec<T>, i: usize, j: usize) -> Vec<T>
         .collect::<Vec<T>>();
 }
 
-pub fn remove_last<T>(x: &mut Vec<T>) -> Vec<T>
+pub fn remove_last<T>(x: &Vec<T>) -> Vec<T>
     where T: Clone
 {
     let n = x.len();
+    if n == 0 {
+        return Vec::<T>::new();
+    }
     return restrict::<T>(x, 0, n-1);
 }
 
 #[allow(dead_code)]
-pub fn remove_first<T>(x: &mut Vec<T>) -> Vec<T>
+pub fn remove_first<T>(x: &Vec<T>) -> Vec<T>
     where T: Clone
 {
     let n = x.len();
+    if n == 0 {
+        return Vec::<T>::new();
+    }
     return restrict::<T>(x, 0, n);
 }