Do proper endian conversions

include/nlohmann/detail/input/binary_reader.hpp

@@ -1853,7 +1853,7 @@ class binary_reader
  }
 
  // reverse byte order prior to conversion if necessary
- if (is_little_endian && !InputIsLittleEndian)
+ if (is_little_endian != InputIsLittleEndian)
  {
  vec[sizeof(NumberType) - i - 1] = static_cast<uint8_t>(current);
  }

include/nlohmann/detail/output/binary_writer.hpp

@@ -1278,7 +1278,7 @@ class binary_writer
  std::memcpy(vec.data(), &n, sizeof(NumberType));
 
  // step 2: write array to output (with possible reordering)
- if (is_little_endian and not OutputIsLittleEndian)
+ if (is_little_endian != OutputIsLittleEndian)
  {
  // reverse byte order prior to conversion if necessary
  std::reverse(vec.begin(), vec.end());

single_include/nlohmann/json.hpp

@@ -8333,7 +8333,7 @@ class binary_reader
  }
 
  // reverse byte order prior to conversion if necessary
- if (is_little_endian && !InputIsLittleEndian)
+ if (is_little_endian != InputIsLittleEndian)
  {
  vec[sizeof(NumberType) - i - 1] = static_cast<uint8_t>(current);
  }
@@ -9746,7 +9746,7 @@ class binary_writer
  std::memcpy(vec.data(), &n, sizeof(NumberType));
 
  // step 2: write array to output (with possible reordering)
- if (is_little_endian and not OutputIsLittleEndian)
+ if (is_little_endian != OutputIsLittleEndian)
  {
  // reverse byte order prior to conversion if necessary
  std::reverse(vec.begin(), vec.end());

test/src/unit-udt.cpp

@@ -599,9 +599,8 @@ struct pod_serializer
  static void to_json(BasicJsonType& j, const T& t) noexcept
  {
  auto bytes = static_cast< const unsigned char*>(static_cast<const void*>(&t));
- std::uint64_t value = bytes[0];
- for (auto i = 1; i < 8; ++i)
- value |= std::uint64_t{bytes[i]} << 8 * i;
+ std::uint64_t value;
+ std::memcpy(&value, bytes, sizeof(value));
  nlohmann::to_json(j, value);
  }
 };