List files in a directory

The filesystem library provides a directory_entry class with directory-related information about a given path. We can use this to create useful directory listings.

How to do it…

In this recipe, we create a directory listing utility using the information in the directory_entry class:

• We start with our namespace alias and formatter specialization for displaying path objects:

  namespace fs = std::filesystem;
  template<>
  struct std::formatter<fs::path>: std::formatter<std::string> {
      template<typename FormatContext>
      auto format(const fs::path& p, FormatContext& ctx) {
          return format_to(ctx.out(), "{}", p.string());
      }
  };

• The directory_iterator class makes it easy to list a directory:

  int main() {
      constexpr const char* fn{ "." };
      ...