I believe tuple is still under development in the standard.  Daniel Krugler is/will be making convincing arguments that a modified form of LWG 2051 (currently NAD Future) is easily acheivable and desirable.  He has demonstrated that a tuple<T...> where all of the T are implicitly convertible from U... should have a tuple constructor that is also implicit, instead of explicit.  This would support the use cases in LWG 2051 while not undermining T... with explicit conversions from U....  This check-in is an experimental implementation of Daniel's work.  I believe this work to be mature enough to warrant inclusion into libc++.  If anyone sees real-world problems that this check in causes, please let me know and I will revert it, and provide the feedback to the LWG.

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@153855 91177308-0d34-0410-b5e6-96231b3b80d8
4 files changed