[Cppcms-users] upgrade_lock and upgrade_to_unique_lock are not implemented in BOOSTER

[CN L. <cn...@gr...>]

Hi!
I am trying to use boost::upgrade_lock and boost::upgrade_to_unique_lock as explained by Dalle in
http://stackoverflow.com/questions/989795/example-for-boost-shared-mutex-multiple-reads-one-write
---begin example code---
void conditional_writer()
{
boost::upgrade_lock< boost::shared_mutex > lock(_access);
// do work here, without anyone having exclusive access

if (something) {
 boost::upgrade_to_unique_lock< boost::shared_mutex > uniqueLock(lock);
// do work here, but now you have exclusive access
}

// do more work here, without anyone having exclusive access
}
---end example code---
It appears that upgrade_lock and upgrade_to_unique_lock are not implemented in booster. Would someone please point me to the alternatives/workaround?
Regards,
CN