use the correct convention for boolean operators

include/nlohmann/detail/input/input_adapters.hpp

@@ -260,7 +260,7 @@ struct wide_string_input_helper<BaseInputAdapter, 2>
             }
             else
             {
-                if (!input.empty())
+                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));
@@ -399,7 +399,7 @@ using contiguous_bytes_input_adapter = decltype(input_adapter(std::declval<const
 template < typename CharT,
            typename std::enable_if <
                std::is_pointer<CharT>::value and
-               !std::is_array<CharT>::value and
+               not std::is_array<CharT>::value and
                std::is_integral<typename std::remove_pointer<CharT>::type>::value and
                sizeof(typename std::remove_pointer<CharT>::type) == 1,
                int >::type = 0 >