Re: gdal 3.9.0, C++17, charconv, gcc7

[Greg Troxel <gdt%lexort.com@localhost>]

Patrick Welche <prlw1%welche.eu@localhost> writes:

> That should have read: USE_CXX_FEATURES and FORCE_CXX_STD

There is a clear difference and today that's not controversial :-(

USE_CXX_FEATURES: ensure that the chosen compiler supports the standard
(except when it doesn't, but that's orthogonal)

FORCE_CXX_STD: as USE_CXX_FEATURES, but also insert --std=c++NN into
CXXFLAGS, so that programs which rely on a particular std but fail to
probe for it and add --std will build.  This is a workaround for bugs
resulting from the practice of assuming that if --std=foo by default on
the developer's box, it will be that way everywhere.  IMHO FORCE_CXX_STD
should required an upstream bug report and URL, just like a patch.