[Boost-users] Meaning of "unspecified" arguments (scoped_lock constructors)

Subject: [Boost-users] Meaning of "unspecified" arguments (scoped_lock constructors)
From: Mark Reginald James (mrj_at_[hidden])
Date: 2008-10-13 05:14:40

Hello,

I haven't been able to discover the meaning of "unspecified"
in things like scoped_lock constructor parameters:

http://www.boost.org/doc/libs/1_36_0/doc/html/boost/interprocess/scoped_lock.html

I'm trying to lock a scoped lock only if the mutex
is not null.  It looks like I need to use one of these
"unspecified" constructors to assign the mutex but not lock
it, so that I can then lock it in an "if" statement if the mutex
is not null.

I'd be grateful for any help.