/// Batch-processing flat combining
void fc_process( typename fc_kernel::iterator itBegin, typename fc_kernel::iterator itEnd )
{
/// Batch-processing flat combining
void fc_process( typename fc_kernel::iterator itBegin, typename fc_kernel::iterator itEnd )
{
typedef typename fc_kernel::iterator fc_iterator;
for ( fc_iterator it = itBegin, itPrev = itEnd; it != itEnd; ++it ) {
switch ( it->op( atomics::memory_order_acquire )) {
typedef typename fc_kernel::iterator fc_iterator;
for ( fc_iterator it = itBegin, itPrev = itEnd; it != itEnd; ++it ) {
switch ( it->op( atomics::memory_order_acquire )) {