Method match

c/tests/pn_test.cpp:164–166

std::string cond_empty::describe() const { return "is empty"; }

bool cond_empty::match(const pn_condition_t &cond) const {
  return !pn_condition_is_set(const_cast<pn_condition_t *>(&cond));
}

cond_matches::cond_matches(std::string name, std::string desc)
    : name_(std::move(name)), desc_(std::move(desc)) {}