It can fit a custom stream object, similarly to std::stringstream, which has state and can accept any relevant objects using operator <<. This way, it will be possible to configure the output formats of the isl_printer. The different between printer_to_file and printer_to_str can be resolved, e.g., with inheritance. It would be nice if printer_to_str behaved similarly to std::stringstream. Finally, callbacks accepting/returning a printer object can accept/return a stream object instead, which is compatible with C++ notion of a stream.
It can fit a custom stream object, similarly to
std::stringstream, which has state and can accept any relevant objects usingoperator <<. This way, it will be possible to configure the output formats of the isl_printer. The different betweenprinter_to_fileandprinter_to_strcan be resolved, e.g., with inheritance. It would be nice ifprinter_to_strbehaved similarly tostd::stringstream. Finally, callbacks accepting/returning a printer object can accept/return a stream object instead, which is compatible with C++ notion of a stream.