cstring header
From Cppwiki
cstring is a C++ Standard Library #include. It is the C++ version of the C Standard Library string.h header.
Functions declared by <cstring>
std::memcpy, std::memmove, std::strcpy, std::strncpy, std::strcat std::strncat, std::memcmp, std::strcmp, std::strcoll, std::strncmp std::strxfrm, std::strcspn, std::strspn, std::strrok, std::memset std::strerror, std::strlen, std::memchr, std::strchr, std::strpbrk std::strrchr, std::strstr
