Subject: bug#34849: Compilation issues with g++ on some files

From: Paul Eggert <[email-masked]>
Date: Tue, 19 Mar 2019 19:12:24 -0700

Eli Zaretskii wrote:
> I believe the intent was to make the existing code be compilable with
> a C++ compiler without introducing any C++ code per se.

Although that may have been the intent, the downside is that a reasonable amount 
of work and testing would have to be done to support it. On the Gnulib side 
we've had some skepticism that this would be worth the hassle; see:

https://lists.gnu.org/r/bug-gnulib/2019-03/msg00060.html

Especially since there is a disciplined way of using the code that (at least for 
Alex's need) appears to work well enough; see:

https://lists.gnu.org/r/bug-gnulib/2019-03/msg00064.html

> many/most of the toolkits and packages we'd
> like to use or be compatible with are written in C++ (HarfBuzz is a
> good recent example)

Sure, but as you mentioned HarfBuzz has a C API, and we needn't tweak or revamp 
Emacs's C code in order to use HarfBuzz. In my experiences toolkits with a C++ 
API but without a C API tend to be less flexible and more of a hassle for C code 
to interface to, and it's not clear we should spend much time catering to them.