IMEX and IDA have public std::functions that must be implemented by the user. I've added a class named Lambdas (better name suggestions?) which implements all the std::functions (e.g., residual, setup_jacobian, solve_linear_system,...) and by defaults these functions call the namesake functions of piDoMUS. This allows greater flexibility. Indeed, when the signals are not enough, a specific function can be completly rewritten as follows
pidomus.lambdas.setup_jacobian = [...](...) ->...
ida works with lambdas
funziona imex ma senza kinsol
get rid of SundialsInterface
fixed constructor without mpi
PR mathLab/deal2lkit#331 is required
removed unused parameter