invalid line using namespace std::tr2::sys;

[berserkrambo]

Vs2019 16.3.1 appears to remove std::tr2::sys, how to fix that without downgrade visual studio?

thanks

[ailovejinx]

Maybe because the namespace std::tr2::sys never exists in C++14. You can delete this line and try to write your code as follow: using namespace std;

#include <experimental/filesystem>
using namespace std::experimental::filesystem;

But this may cause error C1189. You can add macro definition:

#define _SILENCE_EXPERIMENTAL_FILESYSTEM_DEPRECATION_WARNING;

You can also bulid in C++ 17, use new libraries and write as follows to solve the above problems:

#include <filesystem>
using namespace std;
using namespace filesystem;