From 23051df2c71dd3f9698e01de3cbfab0034c6e50e Mon Sep 17 00:00:00 2001
From: Tobias Kux <kux@smart-hmi.de>
Date: Wed, 27 May 2020 13:15:31 +0200
Subject: [PATCH] Cast character to unsigned for comparison

---
 include/nlohmann/detail/input/lexer.hpp | 2 +-
 single_include/nlohmann/json.hpp        | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/include/nlohmann/detail/input/lexer.hpp b/include/nlohmann/detail/input/lexer.hpp
index 4a36ab064d..cf38a813ce 100644
--- a/include/nlohmann/detail/input/lexer.hpp
+++ b/include/nlohmann/detail/input/lexer.hpp
@@ -1367,7 +1367,7 @@ class lexer : public lexer_base<BasicJsonType>
         std::string result;
         for (const auto c : token_string)
         {
-            if ('\x00' <= c and c <= '\x1F')
+            if (static_cast<unsigned char>(c) <= '\x1F')
             {
                 // escape control characters
                 std::array<char, 9> cs{{}};
diff --git a/single_include/nlohmann/json.hpp b/single_include/nlohmann/json.hpp
index 70ce011a8f..38e515966c 100644
--- a/single_include/nlohmann/json.hpp
+++ b/single_include/nlohmann/json.hpp
@@ -9456,7 +9456,7 @@ class lexer : public lexer_base<BasicJsonType>
         std::string result;
         for (const auto c : token_string)
         {
-            if ('\x00' <= c and c <= '\x1F')
+            if (static_cast<unsigned char>(c) <= '\x1F')
             {
                 // escape control characters
                 std::array<char, 9> cs{{}};