From: Lib <lib-bounces@lists.isocpp.org> on behalf of Jonathan Wakely via Lib <lib@lists.isocpp.org>
Sent: Thursday, September 5, 2019 04:51 AM
To: Library Working Group <lib@lists.isocpp.org>; features@isocpp.open-std.org (features@open-std.org) <features@open-std.org>
Cc: Jonathan Wakely <cxx@kayari.org>; JeanHeyd Meneide <phdofthehouse@gmail.com>
Subject: [isocpp-lib] New issue: missing feature test macro for <span>

There is no feature test macro for std::span.

For the purposes of SD-6, I think we want two values: 201803L for the original addition of <span> by P0122R7 (Jacksonville, 2018) and then 201902L for the API changes from P1024R3 (Kona, 2019). The C++ working draft only needs the newer value.

Proposed resolution:

Add a row to [tab:support.ft] in [support.limits.general]:

__cpp_lib_span 201902L <span>