Re: [boost] [variant] Maintainer

14 Jul 2015

      On 07/14/2015 01:03 PM, Peter Dimov wrote:
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Larry Evans wrote:
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What about variant<>, or is that disallowed?
If it is disallowed, then tuple<> should, I guess, also be disallowed.
variant has N(T1)+N(T2)+...+N(Tn) valid values, whereas
tuple has N(T1)*N(T2)*...*N(Tn) valid values, where N(T) is
the number of valid values T has. It follows that variant<> has zero
valid values, whereas tuple<> has one.
Thanks Peter.

To be explicit:

  tuple<> t0;

would be allowed, but:

  variant<> v0;

wouldn't compile because there are "zero valid values"
in a variant<>?