Error(s):

source_file.cpp(7): error C2678: binary '!=': no operator found which takes a left-hand operand of type 'std::istream' (or there is no acceptable conversion)
C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\INCLUDE\exception(343): note: could be 'bool std::operator !=(const std::exception_ptr &,const std::exception_ptr &) throw()' [found using argument-dependent lookup]
C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\INCLUDE\exception(348): note: or       'bool std::operator !=(std::nullptr_t,const std::exception_ptr &) throw()' [found using argument-dependent lookup]
C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\INCLUDE\exception(353): note: or       'bool std::operator !=(const std::exception_ptr &,std::nullptr_t) throw()' [found using argument-dependent lookup]
C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\INCLUDE\system_error(388): note: or       'bool std::operator !=(const std::error_code &,const std::error_code &) noexcept' [found using argument-dependent lookup]
C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\INCLUDE\system_error(395): note: or       'bool std::operator !=(const std::error_code &,const std::error_condition &) noexcept' [found using argument-dependent lookup]
C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\INCLUDE\system_error(402): note: or       'bool std::operator !=(const std::error_condition &,const std::error_code &) noexcept' [found using argument-dependent lookup]
C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\INCLUDE\system_error(409): note: or       'bool std::operator !=(const std::error_condition &,const std::error_condition &) noexcept' [found using argument-dependent lookup]
source_file.cpp(7): note: while trying to match the argument list '(std::istream, nullptr)'