From 92a433ed6987e37e84a94d833248d3c093ce5c6b Mon Sep 17 00:00:00 2001
From: Zengtudor <zengtudor@outlook.com>
Date: Tue, 17 Sep 2024 13:31:49 +0800
Subject: [PATCH] update

---
 src/tools/tools.hpp | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/src/tools/tools.hpp b/src/tools/tools.hpp
index 033d31d..ea24f30 100644
--- a/src/tools/tools.hpp
+++ b/src/tools/tools.hpp
@@ -10,7 +10,7 @@ namespace zt {
     template<typename T>
     class Range{
     private:
-    T _start,_end,_step;
+    const T _start,_end,_step;
     public:
         constexpr Range()=delete;
         constexpr Range(const T start,const T end,const T step)noexcept:_start(start),_end(end),_step(step){}
@@ -18,7 +18,9 @@ namespace zt {
         constexpr Range(const T end)noexcept:Range(1,end,1){}
 
         struct Iterator{
-            T current,step;
+            T current;
+            const T step;
+            
             constexpr Iterator()=delete;
             constexpr Iterator(const T start,const T step)noexcept:current(start),step(step){}
             constexpr bool operator!=(const Iterator &other)const noexcept{
@@ -33,10 +35,10 @@ namespace zt {
             }
         };
 
-        constexpr Iterator begin(){
+        constexpr Iterator begin()const{
             return Iterator(_start,_step);
         }
-        constexpr Iterator end(){
+        constexpr Iterator end()const{
             return Iterator(_end,_step);
         }
     };