When compiling with C++ in MSCV, it defines the __cplusplus macro, but
that's set to an old value and it doesn't represent the current c++
standard version (unless when explicitly requested via `/Zc:__cplusplus`).
So, to enable modern features we should rely on `_MSC_LANG` instead,
which represent the value we care about.
When using an older C++ versions, the glib_typeof() macro is never
defined, as the C++ definition depends on __cplusplus >= 201103L, while the C
definition, which would work, depends on !defined(__cplusplus).
Allow old C++ versions to use the C macro definition for glib_typeof().
Add SPDX license (but not copyright) headers to all files which follow a
certain pattern in their existing non-machine-readable header comment.
This commit was entirely generated using the command:
```
git ls-files glib/*.[ch] | xargs perl -0777 -pi -e 's/\n \*\n \* This library is free software; you can redistribute it and\/or\n \* modify it under the terms of the GNU Lesser General Public/\n \*\n \* SPDX-License-Identifier: LGPL-2.1-or-later\n \*\n \* This library is free software; you can redistribute it and\/or\n \* modify it under the terms of the GNU Lesser General Public/igs'
```
Signed-off-by: Philip Withnall <pwithnall@endlessos.org>
Helps: #1415
It is cleaner to define glib_typeof() in a header included after
gversionmacros.h so we can use GLIB_VERSION_MIN_REQUIRED directly
instead of doing it everywhere glib_typeof() is used.
