Re: [boost] [optional] Regression in develop

Subject: Re: [boost] [optional] Regression in develop
From: Vinnie Falco (vinnie.falco_at_[hidden])
Date: 2017-10-30 09:14:04

On Mon, Oct 30, 2017 at 12:47 AM, Andrzej Krzemienski via Boost
<boost_at_[hidden]> wrote:
> The following is a test case in type_traits by Vinnie Falco:
> https://github.com/boostorg/type_traits/pull/52/commits/9779157a787620d163308afa45cb94ef42391b32

My idea for a fix is to just specialize
`type_traits::is_default_constructible` for `std::pair<T,U>` where U
is a built-in type, by returning `is_default_constructible<T>`. This
solves the problem for Optional, which invokes
`is_default_constructible` with `std::pair<T, bool>` in this specific
case.

Disclosure: Peter Dimov doesn't like it.