tree 3864ecbd71828e5a9b4ca89612fb6cd82fbac38a
parent ba4d4df3ab1382dd07d31fa50d5ab72ba11e76b8
author Eric Fiselier <eric@efcs.ca> 1562181700 +0000
committer Eric Fiselier <eric@efcs.ca> 1562181700 +0000

Fix tuple's conditionally explicit constructors for very weird user
types.

It seems some people like to write types that can explicitly convert
to anything, but cannot be used to explicitly construct anything.

This patch makes tuple tolerate such types, as is required
by the standard.

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@365074 91177308-0d34-0410-b5e6-96231b3b80d8