CodeReview - HTML Tidy Sample Program in C++17

// tidyit.cpp
//
// 11Jun'17 cwhii
//          Improvements based upon Stack Exchange,
//          https://codereview.stackexchange.com/a/165231/2421
//  4May'17 cwhii
//          New, based upon tidylib example,
//          http://api.html-tidy.org/tidy/tidylib_api_5.1.25/tidylib.html
// ---------------------------------------------------------------------------------------------------
#include <sstream>
#include <iostream>
#include <string>
#include <tidy/tidy.h>
#include <tidy/buffio.h>

class TidyDocCPP {
   std::string file_name_;
   TidyDoc tdoc_;
   TidyBuffer errbuf_;
   TidyBuffer outbuf_;
   int rc_;
public:
   TidyDocCPP(const std::string file_name_a):file_name_{file_name_a},tdoc_{tidyCreate()},errbuf_{0},outbuf_{0},rc_{-1} {
      tidyOptSetInt(tdoc_, TidyIndentContent, yes);
      tidyOptSetBool(tdoc_, TidyXhtmlOut, yes);
      tidyOptSetBool(tdoc_, TidyForceOutput,yes);
      }
   ~TidyDocCPP() {
      tidyBufFree(&outbuf_);
      tidyBufFree(&errbuf_);
      tidyRelease(tdoc_);
      }
   TidyDocCPP(TidyDocCPP const&)            = delete;   // Rule of 5.
   TidyDocCPP(TidyDocCPP&&)                 = delete;
   TidyDocCPP& operator=(TidyDocCPP const&) = delete;
   TidyDocCPP& operator=(TidyDocCPP&&)      = delete;
   operator TidyDoc() const {return tdoc_;} // Convert object back to C for use in C tidy functions
   char* getErr(){return (char*)((errbuf_.bp)?(char*)(errbuf_.bp):"");}
   char* getOut(){return (char*)((outbuf_.bp)?(char*)(outbuf_.bp):"");}
   int getRc(){return rc_;}
   bool is_severe_error(int code_a){return ((rc_=code_a)<0);}        // Change to auto in cevelop 1.8.

   bool tidy(){
      return is_severe_error(tidySetErrorBuffer(tdoc_,&errbuf_))
            || is_severe_error(tidyParseFile(tdoc_,file_name_.c_str()))
            || is_severe_error(tidyCleanAndRepair(tdoc_))
            || is_severe_error(tidyRunDiagnostics(tdoc_))
            || is_severe_error(tidySaveBuffer(tdoc_,&outbuf_));
      }
   };

const std::string tidy_file(std::string file_name_a) {               // Change to auto in cevelop 1.8.
   TidyDocCPP tDoc{file_name_a};
   if (tDoc.tidy()){
      std::cerr << "tidyit-A severe error (" << tDoc.getRc() << ") occurred.\n";
      }
   std::cerr << "tidyit-Diagnostics:\n\n" << tDoc.getErr() << "\n";
   const std::string outstr{tDoc.getOut()};
   return outstr;
   }

int main(int argc, char **argv) {
   std::cout << "tidyit-version: so-2\n\n";
   for (std::string name : {"poor.html","good.html"}){
      std::cout << "\nInput file name: " + name << std::endl;
      std::cout << tidy_file(name);
      }
   }