How to read a line from a file before a line break or up to a certain character?

Question

C++ / C#

RAD Studio 10.4 development environment
The program reads data from an XML file, the file opens as follows

std::ifstream bfile;
bfile.open(w_file);
std::wbuffer_convert<std::codecvt_utf8_utf16<wchar_t>> conv(bfile.rbuf());
std::wistream in_file(&conv);

I also tried opening the file like this

std::wifstream in_file;
in_file.open(w_file);
in_file.imbue(locale(in_file.getloc(), new codecvt_utf8<wchar_t, 0x10ffff, consume_header>));

now the data is read like this
in_file>>line;
that is, according to the words, but some of the files contain a lot of data, because of which they can be read for too long.
Tried using
getlne(in_file, line);
but this sends the entire file to line.
When using
getline(in_file, line, '\n');
or
getline(in_file, line, '>');
gives the error "no matching function for call 'getline'.