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Function indeterminate

boost::logic::indeterminate — Keyword and test function for the indeterminate tribool value.


// In header: <boost/logic/tribool.hpp>

BOOST_CONSTEXPR bool indeterminate(tribool x, unspecified dummy = unspecified);


The indeterminate function has a dual role. It's first role is as a unary function that tells whether the tribool value is in the "indeterminate" state. It's second role is as a keyword representing the indeterminate (just like "true" and "false" represent the true and false states). If you do not like the name "indeterminate", and would prefer to use a different name, see the macro BOOST_TRIBOOL_THIRD_STATE.


x.value == tribool::indeterminate_value


Will not throw.