Re: cin - Why Does It Require 2 Returns?

Victor Bazarov <v.bazarov@comcast.invalid> writes:


  Does, ?after every output? mean to have 6 flushes in

::std::cout << "alpha\n"

  (first flush after the output of the 'a', Second flush
  after the output of the 'l', ...)?

  Or do you mean ?for each use of <<", so that

::std::cout << "al" << "pha\n"

  would flush twice?

  One could introduce a global variable:

::std::ostream const out( ::std::cout );

  and then always use ?out? for outputs (instead of
  ::std::cout). Then, - during debugging - it could be
  redefined to refer to some custom ::std::ostream object that
  flushes whenever wanted. For a simple implementation:

::std::ostream const out( ::std::cerr );

  , since IIRC, ?::std::cerr? flushes more often than
  ?::std::cout?.

  PS: See also:

http://www.cplusplus.com/reference/iostream/manipulators/unitbuf/

  .