For compatibility with the C standard library,
the C++ standard library provides the C headers enumerated
in [depr.c.headers], but their use is deprecated in C++.
There are no C++ headers for the C standard library's headers
<stdatomic.h>,
<stdnoreturn.h>,
and <threads.h>,
nor are these headers from the C standard library headers themselves part of C++.
The C headers <complex.h> and
<tgmath.h> do not contain any of the content from
the C standard library and instead merely include other headers from the C++
standard library.