From: Dave (dave_at_[hidden])
Date: 2001-08-27 13:34:44
Fernando Cacciola wrote:
> Currently, a call to has_trivial_constructor() (for example) might return
> false, ... you don't know whether the answer is actually
> meaningful or it means 'I don't know'.
Ah, I see.
If the answer can be yes, no, or "unknown", then by definition
it is not a predicate.
You want to resolve one of three possible states. Two predicates
can resolve four states, so your proposal works. But the proposed
names for the proposed predicates are perplexing. The name of
each predicate should indicate precisely what it resolves. There
is nothing in the name "has_trivial_constructor" to indicate
that one of the two possible results is "I don't know."
-- Dave Miller
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