How do I construct an unbounded Producer-Consumer Queue (or Stack)

Problem

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When using one of the Producer-Consumer classes from Threads.h++ (like RWPCValQueue), how do I specify that there should be no upper bound on the number of items it can hold?

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Cause

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Normally, when constructing one of the Producer-Consumer (PC) classes, you would specify an upper bound for the number of items it can hold. If a producer tries to give the PC object more items than it can hold, the producer is blocked. Consumers are also blocked if they try to read an empty PC object. However, it is often useful not to block when overrunning the queue or stack, excepting only when reading from an empty one.

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Action

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If you want a PC queue or stack to only block when reading from an empty one, and not when writing too many objects into the queue or stack, construct it with the value '0', or don't specify a value (it defaults to 0.) Here are some examples:

RWPCValQueue suzie(5);  // This constructs the queue 
                                   // with an upper limit of 5.

RWPCValQueue curly(0);  // This constructs the queue 
                             // with no upper limit.

RWPCPtrStack smoke;  // The constructs the stack with 
                          // no upper limit.