build message

1>------ Build started: Project: Document, Configuration: Debug Win32 ------
1>cl : Command line warning D9025: overriding '/sdl-' with '/GS-'
1>Document.cpp
1>c:\users\osman\programming\visual_studio_2017\projects\programming_principles_practice_using_c++\document\document\document.h(28): error C2678: binary '<': no operator found which takes a left-hand operand of type 'const std::_List_iterator<std::_List_val<std::_List_simple_types<_Ty>>>' (or there is no acceptable conversion)
1>        with
1>        [
1>            _Ty=Line
1>        ]
1>c:\program files (x86)\microsoft visual studio\2017\community\vc\tools\msvc\14.11.25503\include\system_error(400): note: could be 'bool std::operator <(const std::error_code &,const std::error_code &) noexcept' [found using argument-dependent lookup]
1>c:\program files (x86)\microsoft visual studio\2017\community\vc\tools\msvc\14.11.25503\include\system_error(407): note: or       'bool std::operator <(const std::error_condition &,const std::error_condition &) noexcept' [found using argument-dependent lookup]
1>c:\users\osman\programming\visual_studio_2017\projects\programming_principles_practice_using_c++\document\document\document.h(28): note: while trying to match the argument list '(const std::_List_iterator<std::_List_val<std::_List_simple_types<_Ty>>>, const std::_List_iterator<std::_List_val<std::_List_simple_types<_Ty>>>)'
1>        with
1>        [
1>            _Ty=Line
1>        ]
1>c:\users\osman\programming\visual_studio_2017\projects\programming_principles_practice_using_c++\document\document\document.cpp(75): warning C4018: '<': signed/unsigned mismatch
1>Generating Code...
1>Compiling...
1>main.cpp
1>c:\users\osman\programming\visual_studio_2017\projects\programming_principles_practice_using_c++\document\document\document.h(28): error C2678: binary '<': no operator found which takes a left-hand operand of type 'const std::_List_iterator<std::_List_val<std::_List_simple_types<_Ty>>>' (or there is no acceptable conversion)
1>        with
1>        [
1>            _Ty=Line
1>        ]
1>c:\program files (x86)\microsoft visual studio\2017\community\vc\tools\msvc\14.11.25503\include\system_error(400): note: could be 'bool std::operator <(const std::error_code &,const std::error_code &) noexcept' [found using argument-dependent lookup]
1>c:\program files (x86)\microsoft visual studio\2017\community\vc\tools\msvc\14.11.25503\include\system_error(407): note: or       'bool std::operator <(const std::error_condition &,const std::error_condition &) noexcept' [found using argument-dependent lookup]
1>c:\users\osman\programming\visual_studio_2017\projects\programming_principles_practice_using_c++\document\document\document.h(28): note: while trying to match the argument list '(const std::_List_iterator<std::_List_val<std::_List_simple_types<_Ty>>>, const std::_List_iterator<std::_List_val<std::_List_simple_types<_Ty>>>)'
1>        with
1>        [
1>            _Ty=Line
1>        ]
1>c:\users\osman\programming\visual_studio_2017\projects\programming_principles_practice_using_c++\document\document\main.cpp(16): warning C4018: '<': signed/unsigned mismatch
1>c:\users\osman\programming\visual_studio_2017\projects\programming_principles_practice_using_c++\document\document\main.cpp(38): warning C4018: '>=': signed/unsigned mismatch
1>Generating Code...
1>Done building project "Document.vcxproj" -- FAILED.
========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ==========