Re: 2026Q1 and USE_CXX_FEATURES+=c++20

[Thomas Klausner <wiz%netbsd.org@localhost>]

On Tue, Mar 31, 2026 at 12:01:12PM +0100, Edgar Fuß wrote:
> I've patched that to c++17 (plus filesystem for libheif) in graphics/libheif, 
> print/poppler (Makefile.common, buildlink3.mk) and print/qpdf and built all 
> my packages with the base gcc10.
> 
> So, what problem is this trying to solve?

If upstream says it needs C++20, then I set the variable in the Makefile.

libheif has in its CMakeLists.txt:

set(CMAKE_CXX_STANDARD 20)

qpdf has in its CMakeLists.txt:

if(CXX_NEXT)
  set(CMAKE_CXX_STANDARD 23)
else()
  # See also build-scripts/check-headers
  set(CMAKE_CXX_STANDARD 20)
endif()

I'm not a C++ language lawyer and assume that they have a reason for
setting this.

So this discussion belongs with upstreams IMHO.
 Thomas