message: Use raw pointer instead of std::function
diff: @@ -274,6 +274,7 @@ std::string get_imphash(const Binary& binary, IMPHASH_MODE mode) {
  }
  Import resolve_ordinals(const Import& import, bool strict, bool use_std) {
  + using ordinal_resolver_t = const char*(*)(uint32_t);
  it_const_import_entries entries = import.entries();
  @@ -289,7 +290,7 @@ Import resolve_ordinals(const Import& import, bool strict, bool use_std) {
  std::string name = to_lower(import.name());
  - std::function<const char*(uint32_t)> ordinal_resolver;
  + ordinal_resolver_t ordinal_resolver = nullptr;
  if (use_std) {
  auto it = imphashstd::ordinals_library_tables.find(name);
  if (it != std::end(imphashstd::ordinals_library_tables)) {
  @@ -302,7 +303,7 @@ Import resolve_ordinals(const Import& import, bool strict, bool use_std) {
  }
  }
  - if (not ordinal_resolver) {
  + if (ordinal_resolver == nullptr) {
  std::string msg = "Ordinal lookup table for '" + name + "' not implemented";
  if (strict) {
  throw not_found(msg);
  