# Conflicts:

#	.github/workflows/macos.yml
#	include/nlohmann/detail/input/parser.hpp
#	include/nlohmann/detail/meta/std_fs.hpp
#	include/nlohmann/json.hpp
#	single_include/nlohmann/json.hpp

include/nlohmann/detail/input/parser.hpp

@@ -69,10 +69,10 @@ class parser
   public:
     /// a parser reading from an input adapter
     explicit parser(InputAdapterType&& adapter,
-                    const parser_callback_t<BasicJsonType>& cb = nullptr,
+                    parser_callback_t<BasicJsonType>& cb = nullptr,
                     const bool allow_exceptions_ = true,
                     const bool skip_comments = false)
-        : callback(cb)
+        : callback(std::move(cb))
         , m_lexer(std::move(adapter), skip_comments)
         , allow_exceptions(allow_exceptions_)
     {