This subclause summarizes the explicit changes in headers,
definitions, declarations, or behavior between the C standard library
in the C standard and the parts of the C++ standard library that were
included from the C standard library.
The C++ headers <ccomplex> ([depr.ccomplex.syn])
and <ctgmath> ([depr.ctgmath.syn]), as well
as their corresponding 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.