std::filesystem::file_type - cppreference.com

enum class file_type { none = /* unspecified */, not_found = /* unspecified */, regular = /* unspecified */, directory = /* unspecified */, symlink = /* unspecified */, block = /* unspecified */, character = /* unspecified */, fifo = /* unspecified */, socket = /* unspecified */, unknown = /* unspecified */, /* implementation-defined */ };