I did not have a good experience with boost::variant ... Compile times increased drastically, compiler error messages became enormous and garbled with templates

I did not have a good experience with boost::variant ... Compile times increased drastically, compiler error messages became enormous and garbled with templates, syntax was onerous in places (e.g. "make_recursive_variant"), and identification of types is based on arbitrary index value that is risky to rely on (which() method). I ended up refactoring the whole thing, removing boost::variant and just using the traditional visitor pattern. The only advantage boost::variant really has over traditional C++ visitor pattern is that boost static_visitor functions can have a non-void return type ... Being able to directly return a value in the visitor functions is admittedly very convenient, but the other issues negate this convenience.