Standard C types, functions, constants, etc.
The standard C functions available here, such as snprintf() and time(), are provided by the firmware. Using these functions will not significantly increase the size of your app beyond what is needed to call the function. You may use other standard C functions not listed here, but be aware that not all will successfully be added to your app, and if they are added, your app's binary size will increase accordingly.
Standard locale functions.
Standard math functions.
Standard memory functions.
Standard C-string manipulation.
Standard system time functions.
16-bit unsigned integer number
32-bit unsigned integer number