trouble compiling with vs

[peak torrent]

Context,

I am working on a project for a assignment.
I need to make a c# app with some c++ code in it.
I made 90% of my project in c++ because I hate visual studio.
The last 10% I need to make are the UI and the c# part.

I am making a agenda app and I have a c++ class that does suggestions for where to plan something. These suggestions need to be visualized in c#

Problem

I can compile with g++ but in visual studio when I compile to dll I get errors in a file I didn't even make myself...
Is this a common issue? I can't really find a lot about it online (I might be entering the wrong things)

[jaunty sapphire]

These errors look like you havent included all c files, but rather compiled the c file with just included .h files

[fathom sable]

Show the first error from the output window (not the error list) and the associated code

[peak torrent]

1>C:\Program Files\Microsoft Visual Studio\2022\Community\VC\Tools\MSVC\14.43.34808\include__msvc_string_view.hpp(524,23): error C2027: use of undefined type 'std::basic_ostream<char,std::char_traits<char>>'
1>(compiling source file '../../libs/icalendarlib/date.cpp')

the file is date.cpp from the fork I made from a lib
https://github.com/arthurSmalle/icalendarlib/tree/panner_app

thx in advance btw
if it takes a lot of time you don't really need to look into it
I have accepted it I will just do the assignment partially and make a very fancy TUI in compenstation for the missing GUI

[fathom sable]

Maybe include iostream

[peak torrent]

In the msvc file or the date file?

[fathom sable]

In your file