Boost C++ Libraries

Returns a query iterator pointing at the begin of the query range.

Description

This method returns an iterator which may be used to perform iterative queries. For the information about predicates which may be passed to this method see query().

Synopsis

template<typename Predicates>
const_query_iterator qbegin(Predicates const & predicates)

Modifier(s)

const

Parameter(s)

Returns

The iterator pointing at the begin of the query range.

Example

for ( Rtree::const_query_iterator it = tree.qbegin(bgi::nearest(pt, 10000)) ;
      it != tree.qend() ; ++it )
{
    // do something with value
    if ( has_enough_nearest_values() )
        break;
}

// C++11 (auto)
for ( auto it = tree.qbegin(bgi::nearest(pt, 3)) ; it != tree.qend() ; ++it )
{
    // do something with value
}

// C++14 (generic lambda expression)
std::for_each(tree.qbegin(bgi::nearest(pt, 3)), tree.qend(), [](auto const& val){
    // do something with value
});

Iterator category

ForwardIterator

Throws

If predicates copy throws. If allocation throws.

	Warning
	The modification of the rtree may invalidate the iterators.