From ad8f394835ef5c3f22a0f10cf3b35e3e6e9c2af7 Mon Sep 17 00:00:00 2001
From: Rubidium <rubidium@openttd.org>
Date: Sat, 8 Feb 2025 10:51:47 +0100
Subject: [PATCH] Codechange: introduce string::iterator aware Utf8Decode,
 Utf8Encode and Utf8PrevChar

---
 src/string_func.h | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/src/string_func.h b/src/string_func.h
index eda01a566d..c7c9478dcb 100644
--- a/src/string_func.h
+++ b/src/string_func.h
@@ -76,9 +76,11 @@ inline size_t ttd_strnlen(const char *str, size_t maxlen)
 bool IsValidChar(char32_t key, CharSetFilter afilter);
 
 size_t Utf8Decode(char32_t *c, const char *s);
+inline size_t Utf8Decode(char32_t *c, std::string::iterator &s) { return Utf8Decode(c, &*s); }
 size_t Utf8Encode(char *buf, char32_t c);
 size_t Utf8Encode(std::ostreambuf_iterator<char> &buf, char32_t c);
 size_t Utf8Encode(std::back_insert_iterator<std::string> &buf, char32_t c);
+inline size_t Utf8Encode(std::string::iterator &s, char32_t c) { return Utf8Encode(&*s, c); }
 size_t Utf8TrimString(char *s, size_t maxlen);
 
 
@@ -160,6 +162,13 @@ inline const char *Utf8PrevChar(const char *s)
 	return ret;
 }
 
+inline std::string::iterator Utf8PrevChar(std::string::iterator &s)
+{
+	auto *cur = &*s;
+	auto *prev = Utf8PrevChar(cur);
+	return s - (cur - prev);
+}
+
 size_t Utf8StringLength(const char *s);
 size_t Utf8StringLength(const std::string &str);