From ea2e16c9316f47642453fa8b438e890287f50341 Mon Sep 17 00:00:00 2001
From: blueloveTH <blueloveth@foxmail.com>
Date: Thu, 28 Sep 2023 10:55:48 +0800
Subject: [PATCH] fix toupper and tolower

---
 src/str.cpp | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/src/str.cpp b/src/str.cpp
index c1db0517..0738487d 100644
--- a/src/str.cpp
+++ b/src/str.cpp
@@ -208,13 +208,19 @@ int utf8len(unsigned char c, bool suppress){
 
     Str Str::lower() const{
         std::string copy(data, size);
-        std::transform(copy.begin(), copy.end(), copy.begin(), [](unsigned char c){ return std::tolower(c); });
+        std::transform(copy.begin(), copy.end(), copy.begin(), [](unsigned char c){
+            if('A' <= c && c <= 'Z') return c + ('a' - 'A');
+            return (int)c;
+        });
         return Str(copy);
     }
 
     Str Str::upper() const{
         std::string copy(data, size);
-        std::transform(copy.begin(), copy.end(), copy.begin(), [](unsigned char c){ return std::toupper(c); });
+        std::transform(copy.begin(), copy.end(), copy.begin(), [](unsigned char c){
+            if('a' <= c && c <= 'z') return c - ('a' - 'A');
+            return (int)c;
+        });
         return Str(copy);
     }