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std::basic_ios::good(3)        C++ Standard Libary	 std::basic_ios::good(3)

NAME
     std::basic_ios::good - std::basic_ios::good

Synopsis
	bool good() const;

	Returns  true  if  the most recent I/O operation on the stream completed
     successfully.
	Specifically, returns result of rdstate() == 0.

	See ios_base::iostate for the list of conditions  that	set  the  stream
     status bits.

Parameters
	(none)

Return value
	true if the stream error flags are all false, false otherwise.

Example
     // Run this code

      #include <cstdlib>
      #include <fstream>
      #include <iostream>

      int main()
      {
	  const char* fname = "/tmp/test.txt";
	  std::ofstream ofile{fname};
	  ofile << "10 " << "11 " << "12 " << "non-int";
	  ofile.close();

	  std::ifstream file{fname};
	  if (!file.good())
	  {
	      std::cout << "#1. Opening file test.txt failed - "
			   "one of the error flags is true\n";
	      return EXIT_FAILURE;
	  }

	  // typical C++ I/O loop uses the return value of the I/O function
	  // as the loop controlling condition, operator bool() is used here
	  for (int n; file >> n;)
	      std::cout << n << ' ';
	  std::cout << '\n';

	  if (file.bad())
	  {
	      std::cout << "#2. I/O error while reading - badbit is true\n";
	      return EXIT_FAILURE;
	  }
	  else if (file.eof())
	      std::cout  <<  "#3.  End	of file reached successfully - eofbit is
     true\n"
		  "This is fine even though file.good() is false\n";
	  else if (file.fail())
	      std::cout <<  "#4.  Non-integer  data  encountered  -  failbit  is
     true\n";
      }

Possible output:
      10 11 12
      #4. Non-integer data encountered - failbit is true

See also
	The  following	table  shows  the  value of basic_ios accessors (good(),
     fail(), etc.)
	for all possible combinations of ios_base::iostate flags:

	     ios_base::iostate flags basic_ios accessors
	     eofbit  failbit  badbit good() fail() bad() eof() operator bool op-
     erator!
	     false    false	 false	  true	   false    false   false   true
     false
	     false     false	  true	   false    true     true   false  false
     true
	     false    true	false	 false	  true	   false   false   false
     true
	     false     true	  true	   false    true     true   false  false
     true
	     true     false	 false	  false    false    false   true    true
     false
	     true      false	  true	   false    true     true   true   false
     true
	     true     true	false	 false	  true	   false   true    false
     true
	     true      true	  true	   false    true     true   true   false
     true

http://cppreference.com 	   2024.06.10		 std::basic_ios::good(3)
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