[PATCH] Fix tuple<A> to A conversion in SFINAE for tuple(_Up...) constructor
eric at efcs.ca
Fri May 1 00:04:29 PDT 2015
Tuple is tricky. If there is a bug in tuple you can bet that SFINAE is both the problem and the solution. constexpr constructors are becoming a frequent problem in the tuple SFINAE because they tend to cause hard compile errors. The SFINAE you added could easily introduce an almost identical bug in a different scenario.
Another reason I'm so hesitant to move forward with this patch is because they essentially contradicts http://reviews.llvm.org/D8178.
The first step to solving both of these bugs is to drastically increase the test coverage of tuple. The tests need to cover a much wider range of types than they currently do. Until then I think both these patches will need to wait in limbo.
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