问题
I want to simplify my code by using boost::lambda. Here is my code:
// Declare container:
typedef std::map< PageId, Page* > Pages;
Pages m_pages;
// For serialization:
template < class DataType > TPair< DataType > makePair( const std::string& identification, const DataType& dataType )
{
return TPair< DataType >( identification, dataType );
}
#define SERILIZE_CLASS( _value ) ::Tools::Serilizer::makePair< ::Tools::Serilizer::Serilizable >( EXTRACT_NAME( _value ), _value )
// This does work and should be simplified by....
for( BOOST_AUTO( i, m_pages.begin( ) ); i != m_pages.end( ); ++i )
{
obj << SERILIZE_CLASS( *i->second );
}
// this code but itdoes not compile
std::for_each( m_pages.begin( ), m_pages.end( ),
obj << SERILIZE_CLASS( boost::lambda::bind( &Pages::value_type::second, boost::lambda::_1 ) ) );
Finally this is the resulting error code:
error C2664: 'Tools::Serilizer::makePair' : cannot convert parameter 2 from 'const boost::lambda::lambda_functor' to 'const Tools::Serilizer::Serilizable &'
Any hints how to solve this ?
回答1:
I think your problem is mixing lambdas (that is functions) with the values returned by the lambdas:
For example:
boost::lambda::bind( &Pages::value_type::second, boost::lambda::_1 )
Returns a function.
So calling serialize_class(...)
with its result doesn't make sense to me.
That said, I haven't studied your code in much depth. I found it a bit confusing.
来源:https://stackoverflow.com/questions/10163980/boostlambda-stdmap