From 87a1d75bf1c1ee964e8eed4a6686544ae3b44116 Mon Sep 17 00:00:00 2001
From: Arthur Sonzogni <sonzogniarthur@gmail.com>
Date: Tue, 18 May 2021 21:48:32 +0200
Subject: [PATCH] Fix unsigned/signed comparison issues. (#103)

Seen here:
https://github.com/VedantParanjape/simpPRU/runs/2613171696
---
 include/ftxui/screen/string.hpp |  2 ++
 src/ftxui/screen/wcwidth.cpp    | 20 ++++++++++++++------
 2 files changed, 16 insertions(+), 6 deletions(-)

diff --git a/include/ftxui/screen/string.hpp b/include/ftxui/screen/string.hpp
index 15849a4e..ad312b5b 100644
--- a/include/ftxui/screen/string.hpp
+++ b/include/ftxui/screen/string.hpp
@@ -12,7 +12,9 @@ std::wstring to_wstring(T s) {
   return to_wstring(std::to_string(s));
 }
 
+int wchar_width(char32_t);
 int wchar_width(wchar_t);
+int wchar_width_cjk(char32_t);
 int wchar_width_cjk(wchar_t);
 int wstring_width(const std::wstring&);
 int wstring_width_cjk(const std::wstring&);
diff --git a/src/ftxui/screen/wcwidth.cpp b/src/ftxui/screen/wcwidth.cpp
index 7791a3e4..a23ce3bf 100644
--- a/src/ftxui/screen/wcwidth.cpp
+++ b/src/ftxui/screen/wcwidth.cpp
@@ -67,12 +67,12 @@ namespace ftxui {
 
 namespace {
 struct interval {
-  int first;
-  int last;
+  char32_t first;
+  char32_t last;
 };
 
 /* auxiliary function for binary search in interval table */
-int bisearch(wchar_t ucs, const struct interval* table, int max) {
+int bisearch(char32_t ucs, const struct interval* table, int max) {
   int min = 0;
   int mid;
 
@@ -120,11 +120,11 @@ int bisearch(wchar_t ucs, const struct interval* table, int max) {
  *      ISO 8859-1 and WGL4 characters, Unicode control characters,
  *      etc.) have a column width of 1.
  *
- * This implementation assumes that wchar_t characters are encoded
+ * This implementation assumes that char32_t characters are encoded
  * in ISO 10646.
  */
 
-int wchar_width(wchar_t ucs) {
+int wchar_width(char32_t ucs) {
   /* sorted list of non-overlapping intervals of non-spacing characters */
   /* generated by "uniset +cat=Me +cat=Mn +cat=Cf -00AD +1160-11FF +200B c" */
   static const struct interval combining[] = {
@@ -214,7 +214,7 @@ int wchar_width(wchar_t ucs) {
  * the traditional terminal character-width behaviour. It is not
  * otherwise recommended for general use.
  */
-int wchar_width_cjk(wchar_t ucs) {
+int wchar_width_cjk(char32_t ucs) {
   /* sorted list of non-overlapping intervals of East Asian Ambiguous
    * characters, generated by "uniset +WIDTH-A -cat=Me -cat=Mn -cat=Cf c" */
   static const struct interval ambiguous[] = {
@@ -278,6 +278,14 @@ int wchar_width_cjk(wchar_t ucs) {
   return wchar_width(ucs);
 }
 
+int wchar_width(wchar_t ucs) {
+  return wchar_width(char32_t(ucs));
+}
+
+int wchar_width_cjk(wchar_t ucs) {
+  return wchar_width_cjk(char32_t(ucs));
+}
+
 int wstring_width(const std::wstring& text) {
   int width = 0;