https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114841
--- Comment #1 from Jason Merrill <jason at gcc dot gnu.org> --- Matheus' suggested wording: "When performing deduction such that both A and P are template template params, and A is the template name of a template specialization, instead of just deducing A in that case, we synthesize a new template parameter from A, filling it's parameters with defaults coming from their corresponding template specialization argument."
