json_view: no save() and load() on big-endian targets

The image format is little-endian only. Instead of throwing
type_error.320 at runtime, save_image(), load_image() and the members
save() and load() do not exist on a big-endian target, so a call fails to
compile, like set() on a read-only document. type_error.320 remains for
saving a discarded document.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>

include/nlohmann/detail/view/node.hpp

@@ -47,7 +47,7 @@ enum class node_kind : std::uint8_t
     null = static_cast<std::uint8_t>(value_t::null),
     object = static_cast<std::uint8_t>(value_t::object),
     array = static_cast<std::uint8_t>(value_t::array),
-    string = static_cast<std::uint8_t>(value_t::string),
+    string = static_cast<std::uint8_t>(value_t::string), // NOLINT(build/include_what_you_use): an enumerator, not std::string
     boolean = static_cast<std::uint8_t>(value_t::boolean),
     number_integer = static_cast<std::uint8_t>(value_t::number_integer),
     number_unsigned = static_cast<std::uint8_t>(value_t::number_unsigned),

single_include/nlohmann/json_view.hpp

@@ -245,7 +245,7 @@ enum class node_kind : std::uint8_t
     null = static_cast<std::uint8_t>(value_t::null),
     object = static_cast<std::uint8_t>(value_t::object),
     array = static_cast<std::uint8_t>(value_t::array),
-    string = static_cast<std::uint8_t>(value_t::string),
+    string = static_cast<std::uint8_t>(value_t::string), // NOLINT(build/include_what_you_use): an enumerator, not std::string
     boolean = static_cast<std::uint8_t>(value_t::boolean),
     number_integer = static_cast<std::uint8_t>(value_t::number_integer),
     number_unsigned = static_cast<std::uint8_t>(value_t::number_unsigned),