Boost C++ Libraries

...one of the most highly regarded and expertly designed C++ library projects in the world. — Herb Sutter and Andrei Alexandrescu, C++ Coding Standards

libs/test/doc/examples/example28.run-fail.cpp

//  (C) Copyright Gennadiy Rozental 2011-2015.
//  Distributed under the Boost Software License, Version 1.0.
//  (See accompanying file LICENSE_1_0.txt or copy at
//  http://www.boost.org/LICENSE_1_0.txt)

//  See http://www.boost.org/libs/test for the library home page.

//[example_code
#define BOOST_TEST_MODULE example
#include <boost/test/included/unit_test.hpp>
#include <boost/test/tools/output_test_stream.hpp>
using boost::test_tools::output_test_stream;

BOOST_AUTO_TEST_CASE( test )
{
  output_test_stream output;
  int i=2;
  output << "i=" << i;
  BOOST_TEST( !output.is_empty( false ) );
  BOOST_TEST( output.check_length( 3, false ) );
  BOOST_TEST( output.is_equal( "i=3" ) );
}
//]