std::ios_base::seekdir(3)

NAME
std::ios_base::seekdir - std::ios_base::seekdir

Synopsis
   typedef /*implementation defined*/ seekdir;
   static constexpr seekdir beg = /*implementation defined*/
   static constexpr seekdir end = /*implementation defined*/
   static constexpr seekdir cur = /*implementation defined*/
   Specifies file seeking direction type. The following constants are defined:
   Constant Explanation
   beg the beginning of a stream
   end the ending of a stream
   cur the current position of stream position indicator

Example
// Run this code
 #include <iostream>
 #include <sstream>
 #include <string>
 int main()
 {
     std::istringstream in("Hello, World!");
     std::string word1, word2, word3, word4, word5;
     in >> word1;
     in.seekg(0, std::ios_base::beg); // <- rewind
     in >> word2;
     in.seekg(1, std::ios_base::cur); // -> seek from cur pos toward the end
     in >> word3;
     in.seekg(-6, std::ios_base::cur); // <- seek from cur pos (end) toward begin
     in >> word4;
     in.seekg(-6, std::ios_base::end); // <- seek from end toward begin
     in >> word5;
     std::cout << "word1 = " << word1 << '\n'
               << "word2 = " << word2 << '\n'
               << "word3 = " << word3 << '\n'
               << "word4 = " << word4 << '\n'
               << "word5 = " << word5 << '\n';
 }

Output:
 word1 = Hello,
 word2 = Hello,
 word3 = World!
 word4 = World!
 word5 = World!

See also
   seekg sets the input position indicator
              (public member function of std::basic_istream<CharT,Traits>)
   seekp sets the output position indicator
              (public member function of std::basic_ostream<CharT,Traits>)
   pubseekoff invokes seekoff()
              (public member function of std::basic_streambuf<CharT,Traits>)