Added simple operators << and >> to optional<>

[SVN r32533]

include/boost/optional/optional_io.hpp

@@ -0,0 +1,64 @@
+// Copyright (C) 2005, Fernando Luis Cacciola Carballal.
+//
+// Use, modification, and distribution is subject to 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/lib/optional for documentation.
+//
+// You are welcome to contact the author at:
+//  fernando_cacciola@hotmail.com
+//
+#ifndef BOOST_OPTIONAL_OPTIONAL_IO_FLC_19NOV2002_HPP
+#define BOOST_OPTIONAL_OPTIONAL_IO_FLC_19NOV2002_HPP
+
+#include<ostream>
+#include<istream>
+
+
+#include "boost/optional/optional.hpp"
+#include "boost/utility/value_init.hpp"
+
+namespace boost
+{
+
+template<class CharType, class CharTrait, class T>
+inline
+std::basic_ostream<CharType, CharTrait>&
+operator<<(std::basic_ostream<CharType, CharTrait>& out, optional<T> const& v)
+{
+  if ( out.good() )
+  {
+    if ( !v )
+         out << "--" ;
+    else out << ' ' << *v ;
+  }
+
+  return out;
+}
+
+template<class CharType, class CharTrait, class T>
+inline
+std::basic_istream<CharType, CharTrait>&
+operator>>(std::basic_istream<CharType, CharTrait>& in, optional<T>& v)
+{
+  if ( in.good() )
+  {
+    int d = in.get();
+    if ( d == ' ' )
+    {
+      T x ;
+      in >> x;
+      v = x ;
+    }
+    else
+      v = optional<T>() ;
+  }
+
+  return in;
+}
+
+} // namespace boost
+
+#endif
+

test/Jamfile

@@ -22,6 +22,7 @@ DEPENDS all : test ;
     [ run optional_test_tie.cpp ]
     [ run optional_test_ref.cpp ]
     [ run optional_test_inplace.cpp ]
+    [ run optional_test_io.cpp ]
     [ compile-fail optional_test_fail1.cpp ]
     [ compile-fail optional_test_fail2.cpp ]
     [ compile-fail optional_test_fail3a.cpp ]

test/optional_test_io.cpp

@@ -0,0 +1,89 @@
+// Copyright (C) 2003, Fernando Luis Cacciola Carballal.
+//
+// Use, modification, and distribution is subject to 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/lib/optional for documentation.
+//
+// You are welcome to contact the author at:
+//  fernando_cacciola@hotmail.com
+//
+#include<stdexcept>
+#include<string>
+#include<sstream>
+
+#define BOOST_ENABLE_ASSERT_HANDLER
+
+#include "boost/optional/optional.hpp"
+#include "boost/optional/optional_io.hpp"
+#include "boost/none.hpp"
+
+#include "boost/test/minimal.hpp"
+
+#ifdef ENABLE_TRACE
+#define TRACE(msg) std::cout << msg << std::endl ;
+#else
+#define TRACE(msg)
+#endif
+
+namespace boost {
+
+void assertion_failed (char const * expr, char const * func, char const * file, long )
+{
+  using std::string ;
+  string msg =  string("Boost assertion failure for \"")
+               + string(expr)
+               + string("\" at file \"")
+               + string(file)
+               + string("\" function \"")
+               + string(func)
+               + string("\"") ;
+
+  TRACE(msg);
+
+  throw std::logic_error(msg);
+}
+
+}
+
+using namespace std ;
+using namespace boost ;
+
+template<class Opt>
+void test2( Opt o, Opt buff )
+{
+  stringstream s ;
+
+  s << o ;
+  s >> buff ;
+
+  BOOST_ASSERT( buff == o ) ;
+}
+
+
+template<class T>
+void test( T v, T w )
+{
+  test2( make_optional(v), optional<T>  ());
+  test2( make_optional(v), make_optional(w));
+  test2( optional<T>  () , optional<T>  ());
+  test2( optional<T>  () , make_optional(w));
+}
+
+int test_main( int, char* [] )
+{
+  try
+  {
+    test(1,2);
+    test(string("hello"),string("buffer"));
+    test(string(""),string("buffer"));
+  }
+  catch ( ... )
+  {
+    BOOST_ERROR("Unexpected Exception caught!");
+  }
+
+  return 0;
+}
+