Thanks for the report. I think the bug is that we need a second
character in the syntax table entry, to set the correct matching
delimiter.
Does the following patch solve this issue and bug#60049?
I don't know how this can work if '<' is going to be used to input
the less-than operator. I think more complex syntax-propertization
functionality is going to be needed here. I don't have a tree-sitter
build to test, but I'd say that the tree-sitter backend should be asked
about what kind of '<' and '>' we're talking about. AFAICT, just
saying that '<' has the delimiter syntax in C++ is wrong. It's not
like '(' or '{.'
João