c++ - On platforms where pthread_t is numeric, is 0 guaranteed to be an invalid value? -

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this question has answer here:

pthread_t (as returned pthread_self()) opaque type, on platforms numeric, example typedefed unsigned long. on these platforms, 0 invalid pthread_t value? -1?

if wanted value either pthread_t or invalid, i'd use boost::optional<pthread_t> or std::optional<pthread_t> c++1y.

this has little overhead (bytes), expresses want (this value may or may not pthread_t), , doesn't rely on platform-specific behavior.


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