What parts of the C standard library are not covered (the rest) by the C ++ standard library?

Question

The C ++ library contains the same definitions as the C language library

However, the C ++ library duplicates (/ extends) some functions of the C library in the headers of the non-C library. For example, the C library has <string.h>, and the C ++ library has both <cstring> and <string>; the C library has <time.h>, and the C + library has both <ctime> and <chrono>.

If I need a string class, I guess I should use <string> instead of <cstring>, because <string> can benefit from all non-C functions in C ++ (like exceptions). But in the C library there is functionality that does not exist in any other form in the C ++ library. For example, I could not find anything like memcpy and memcmp outside of <cstring>.

What parts of the C library have no analogues in the headers of the non-C library?

(If the version uses the C ++ version, I'm interested in C ++ 11.)

Answer 1

There are not many headings, so let's just list them. Some may be replaced by language tools rather than libraries. (I did not list every function in every header, so maybe I missed an odd function that has no C ++ alternative when most of its colleagues do it.)

C library C++ alternatives assert.h Exceptions complex.h <complex> ctype.h None (or maybe <locale>, if you want to jump down that rabbit-hole) errno.h None (but only applies to C functions) fenv.h None float.h <limits> inttypes.h (See breakdown) formatting <iostream> strto... <string> (C++11), <sstream> imaxabs std::abs overloads imaxdiv std::div overloads iso646.h Language locale.h <locale> math.h None (extended with C++ overloads) setjmp.h Exceptions signal.h None stdarg.h Variadic templates (C++11) stdbool.h Language stddef.h None stdint.h None stdio.h <iostream> etc. stdlib.h (See breakdown) atof etc. <sstream>, <string> (C++11) rand etc. <random> (C++11) malloc etc. new, containers abort etc. None bsearch etc. <algorithm> abs etc. None (extended with C++ overloads) mb strings None string.h <string>, <algorithm> tgmath.h <cmath> (C++ overloads) time.h <chrono> (C++11) wchar.h <iostream> etc. wctype.h None 

Summarizing:

What parts of the C library have no analogues in the headers of the non-C library?

[w]ctype.h , errno.h , fenv.h , fenv.h , math.h , signal.h , stddef.h , stdint.h , some of stdlib.h . Before C ++ 11 also stdarg.h , time.h and more stdlib.h