ExistingFileValidator fail for file > 2GB on Windows

[zyzheng]

When using with a video file that is larger than 2GB, ExistingFileValidator always fails even if the file actually exists.

From the code, it's using stat to check file stats. According to Microsoft document, it seems that function only support up to 32bit file length, which I assume is the cause for this problem.

I think using _stat64 on Windows should fix it, but not sure about other operating system.

[henryiii]

I believe other platforms return 64-bits from stat. Probably needs a check for windows + 64 bit...

[steffenb7333]

Since it is a CMAKE-define (CLI11_CXX_STD) would it not be an option to use std::filesystem::* if CLI11 is/was compiled using c++17 and/or a Feature Testing Macro indicates it is available?