start help

src/cxxopts.cpp

@@ -35,6 +35,38 @@ namespace cxxopts
 
     std::basic_regex<char> option_specifier
       ("(([a-zA-Z]),)?([a-zA-Z][-_a-zA-Z]+)");
+
+    std::string
+    format_option
+    (
+      const std::string& s,
+      const std::string& l,
+      bool has_arg
+    )
+    {
+      std::string result = "  ";
+
+      if (s.size() > 0)
+      {
+        result += "-" + s + ",";
+      }
+      else
+      {
+        result += "   ";
+      }
+
+      if (l.size() > 0)
+      {
+        result += " --" + l;
+      }
+
+      if (has_arg)
+      {
+        result += " arg";
+      }
+
+      return result;
+    }
   }
 
 OptionAdder
@@ -270,6 +302,8 @@ Options::add_option
   }
 
   //add the help details
+  auto& options = m_help[""];
+  options.push_back(HelpDetails{s, l, desc, value->has_arg()});
 }
 
 void
@@ -290,13 +324,29 @@ Options::add_one_option
 std::string
 Options::help() const
 {
+  typedef std::vector<std::pair<std::string, std::string>> OptionHelp;
+
   auto group = m_help.find("");
   if (group == m_help.end())
   {
     return "";
   }
 
-  return "";
+  OptionHelp format;
+
+  size_t longest = 0;
+
+  std::string result;
+
+  for (const auto& o : group->second)
+  {
+    auto s = format_option(o.s, o.l, o.has_arg);
+    longest = std::max(longest, s.size());
+    format.push_back(std::make_pair(s, std::string()));
+    result += s + "\n";
+  }
+
+  return result;
 }
 
 }

src/cxxopts.hpp

@@ -286,16 +286,12 @@ namespace cxxopts
     int m_count;
   };
 
-  class HelpDetails
+  struct HelpDetails
   {
-    public:
-    HelpDetails();
-
-    private:
-    std::string m_short;
-    std::string m_long;
-    std::string m_description;
-    bool m_arg;
+    std::string s;
+    std::string l;
+    std::string desc;
+    bool has_arg;
   };
 
   class Options

src/main.cpp

@@ -38,6 +38,7 @@ int main(int argc, char* argv[])
       ("b,bob", "Bob")
       ("f,file", "File", cxxopts::value<std::vector<std::string>>())
       ("positional", "Positional arguments", cxxopts::value<std::string>())
+      ("help", "Print help")
     ;
 
     options.parse_positional("positional");
@@ -66,7 +67,7 @@ int main(int argc, char* argv[])
 
     if (options.count("help"))
     {
-      //std::cout << options.print_help();
+      std::cout << options.help() << std::endl;
     }
 
     if (options.count("positional"))