expected( value_type const & rhs )
: has_value( true )
{
contained.construct_value( rhs );
}
expected( expected const & rhs )
: has_value( rhs.has_value )
{
if ( has_value ) contained.construct_value( rhs.contained.value() );
else contained.construct_error( rhs.contained.error() );
}
void initialize_value( V const & v )
{
assert( ! has_value );
contained.construct_value( v );
has_value = true;
}