Anything related to C or C++ standard library functions `putchar` (C) or `std::putchar` (C++). These functions are used to write a single character to the standard output stream `stdout`.
Anything related to C or C++ standard library functions putchar
(defined in <stdio.h>
C standard header) or std::putchar
(defined in <cstdio>
C++ standard header). These functions are used to write a single character to the standard output stream stdout
.
See CPPreference.com: