Error(s):

source_file.cpp(13): error C2668: 'f': ambiguous call to overloaded function
source_file.cpp(7): note: could be 'void f(std::function<void (std::unique_ptr<Message,std::default_delete<_Ty>>)>)'
        with
        [
            _Ty=Message
        ]
source_file.cpp(6): note: or       'void f(std::function<void (std::shared_ptr<Message>)>)'
source_file.cpp(13): note: while trying to match the argument list '(main::<lambda_74e2623b229b211f81b1a3c3b65ece6f>)'
source_file.cpp(14): error C2668: 'f': ambiguous call to overloaded function
source_file.cpp(7): note: could be 'void f(std::function<void (std::unique_ptr<Message,std::default_delete<_Ty>>)>)'
        with
        [
            _Ty=Message
        ]
source_file.cpp(6): note: or       'void f(std::function<void (std::shared_ptr<Message>)>)'
source_file.cpp(14): note: while trying to match the argument list '(main::<lambda_21839c5d74c88cf6484b5fc354d78716>)'
Microsoft (R) C/C++ Optimizing Compiler Version 19.00.23506 for x64