From ae04426c856ef5f5bd6d54fea069836ba3499f94 Mon Sep 17 00:00:00 2001
From: Niels Lohmann <mail@nlohmann.me>
Date: Mon, 8 Jun 2020 20:07:15 +0200
Subject: [PATCH] :checkered_flag: fix for MSVC (see
 https://github.com/nlohmann/json/pull/2178#issuecomment-640622532)

---
 .../nlohmann/detail/input/input_adapters.hpp  | 13 +++++---
 single_include/nlohmann/json.hpp              | 31 ++++++++++---------
 2 files changed, 25 insertions(+), 19 deletions(-)

diff --git a/include/nlohmann/detail/input/input_adapters.hpp b/include/nlohmann/detail/input/input_adapters.hpp
index 923a7aaa..ed9db0f6 100644
--- a/include/nlohmann/detail/input/input_adapters.hpp
+++ b/include/nlohmann/detail/input/input_adapters.hpp
@@ -339,15 +339,18 @@ struct iterator_input_adapter_factory
     }
 };
 
-// This test breaks astyle formatting when inlined in a template specialization.
 template<typename T>
-inline constexpr bool is_iterator_of_multibyte()
+struct is_iterator_of_multibyte
 {
-    return sizeof(typename std::iterator_traits<T>::value_type) > 1;
-}
+    using value_type = typename std::iterator_traits<T>::value_type;
+    enum
+    {
+        value = sizeof(value_type) > 1
+    };
+};
 
 template<typename IteratorType>
-struct iterator_input_adapter_factory<IteratorType, enable_if_t<is_iterator_of_multibyte<IteratorType>()>>
+struct iterator_input_adapter_factory<IteratorType, enable_if_t<is_iterator_of_multibyte<IteratorType>::value>>
 {
     using iterator_type = IteratorType;
     using char_type = typename std::iterator_traits<iterator_type>::value_type;
diff --git a/single_include/nlohmann/json.hpp b/single_include/nlohmann/json.hpp
index dd9b21c4..e45a756f 100644
--- a/single_include/nlohmann/json.hpp
+++ b/single_include/nlohmann/json.hpp
@@ -4669,15 +4669,15 @@ struct wide_string_input_helper<BaseInputAdapter, 2>
             }
             else if (wc <= 0x7FF)
             {
-                utf8_bytes[0] = static_cast<std::char_traits<char>::int_type>(0xC0u | ((wc >> 6u)));
-                utf8_bytes[1] = static_cast<std::char_traits<char>::int_type>(0x80u | (wc & 0x3Fu));
+                utf8_bytes[0] = static_cast<std::char_traits<char>::int_type>(0xC0u | ((static_cast<unsigned int>(wc) >> 6u)));
+                utf8_bytes[1] = static_cast<std::char_traits<char>::int_type>(0x80u | (static_cast<unsigned int>(wc) & 0x3Fu));
                 utf8_bytes_filled = 2;
             }
             else if (0xD800 > wc or wc >= 0xE000)
             {
-                utf8_bytes[0] = static_cast<std::char_traits<char>::int_type>(0xE0u | ((wc >> 12u)));
-                utf8_bytes[1] = static_cast<std::char_traits<char>::int_type>(0x80u | ((wc >> 6u) & 0x3Fu));
-                utf8_bytes[2] = static_cast<std::char_traits<char>::int_type>(0x80u | (wc & 0x3Fu));
+                utf8_bytes[0] = static_cast<std::char_traits<char>::int_type>(0xE0u | ((static_cast<unsigned int>(wc) >> 12u)));
+                utf8_bytes[1] = static_cast<std::char_traits<char>::int_type>(0x80u | ((static_cast<unsigned int>(wc) >> 6u) & 0x3Fu));
+                utf8_bytes[2] = static_cast<std::char_traits<char>::int_type>(0x80u | (static_cast<unsigned int>(wc) & 0x3Fu));
                 utf8_bytes_filled = 3;
             }
             else
@@ -4685,7 +4685,7 @@ struct wide_string_input_helper<BaseInputAdapter, 2>
                 if (JSON_HEDLEY_UNLIKELY(not input.empty()))
                 {
                     const auto wc2 = static_cast<unsigned int>(input.get_character());
-                    const auto charcode = 0x10000u + (((wc & 0x3FFu) << 10u) | (wc2 & 0x3FFu));
+                    const auto charcode = 0x10000u + (((static_cast<unsigned int>(wc) & 0x3FFu) << 10u) | (wc2 & 0x3FFu));
                     utf8_bytes[0] = static_cast<std::char_traits<char>::int_type>(0xF0u | (charcode >> 18u));
                     utf8_bytes[1] = static_cast<std::char_traits<char>::int_type>(0x80u | ((charcode >> 12u) & 0x3Fu));
                     utf8_bytes[2] = static_cast<std::char_traits<char>::int_type>(0x80u | ((charcode >> 6u) & 0x3Fu));
@@ -4761,15 +4761,18 @@ struct iterator_input_adapter_factory
     }
 };
 
-// This test breaks astyle formatting when inlined in a template specialization.
 template<typename T>
-inline constexpr bool is_iterator_of_multibyte()
+struct is_iterator_of_multibyte
 {
-    return sizeof(typename std::iterator_traits<T>::value_type) > 1;
-}
+    using value_type = typename std::iterator_traits<T>::value_type;
+    enum
+    {
+        value = sizeof(value_type) > 1
+    };
+};
 
 template<typename IteratorType>
-struct iterator_input_adapter_factory<IteratorType, enable_if_t<is_iterator_of_multibyte<IteratorType>()>>
+struct iterator_input_adapter_factory<IteratorType, enable_if_t<is_iterator_of_multibyte<IteratorType>::value>>
 {
     using iterator_type = IteratorType;
     using char_type = typename std::iterator_traits<iterator_type>::value_type;
@@ -8177,7 +8180,7 @@ class lexer : public lexer_base<BasicJsonType>
     using token_type = typename lexer_base<BasicJsonType>::token_type;
 
     explicit lexer(InputAdapterType&& adapter)
-        : ia(std::move(adapter)), decimal_point_char(static_cast<char_type>(get_decimal_point())) {}
+        : ia(std::move(adapter)), decimal_point_char(static_cast<char_int_type>(get_decimal_point())) {}
 
     // delete because of pointer members
     lexer(const lexer&) = delete;
@@ -9282,7 +9285,7 @@ scan_number_done:
     token_type scan_literal(const char_type* literal_text, const std::size_t length,
                             token_type return_type)
     {
-        assert(current == literal_text[0]);
+        assert(std::char_traits<char_type>::to_char_type(current) == literal_text[0]);
         for (std::size_t i = 1; i < length; ++i)
         {
             if (JSON_HEDLEY_UNLIKELY(std::char_traits<char_type>::to_char_type(get()) != literal_text[i]))
@@ -9587,7 +9590,7 @@ scan_number_done:
     number_float_t value_float = 0;
 
     /// the decimal point
-    const char_type decimal_point_char = '.';
+    const char_int_type decimal_point_char = '.';
 };
 }  // namespace detail
 }  // namespace nlohmann