[PATCHv2] do not throw in std::make_exception_ptr

[Jonathan Wakely]

On 21/10/16 12:44 +0100, Jonathan Wakely wrote:
>On 21/10/16 14:36 +0300, Gleb Natapov wrote:
>>On Thu, Oct 20, 2016 at 11:53:49PM -0400, Ryan Burn wrote:
>>>Are exception classes required to support emplace new construction
>>>like that? With this change, Intel's TBB library no longer compiles
>>>because its exception class declares it's own new operator (see
>>>https://github.com/wjakob/tbb/blob/master/include/tbb/tbb_exception.h):
>>>
>>Can you test this patch please:
>
>That doesn't help, the overloaded new still prevents placement new.
>Dammit.
>
>I'll see what we can do ...


We should be able to us SFINAE to detect when the placement
new-expression is valid.