Arduino F(): what does it actually do

Question

I have asked a similar question before, but I realize that I can\'t make heads or tails of the macrology and templateness. I\'m a C (rather than C++) programmer.

Wha

Answer 1

BTW. For th ESP32 library, both of these functions are defined in the following files:

# PSTR :  ../Arduino/hardware/espressif/esp32/cores/esp32/pgmspace.h
# F    :  ../Arduino/hardware/espressif/esp32/cores/esp32/WString.h

and the F(x):

// an abstract class used as a means to proide a unique pointer type
// but really has no body
class __FlashStringHelper;
#define F(string_literal) (reinterpret_cast(PSTR(string_literal)))
...

Also for ESP32, PSTR(x) is not needed and is just x: #define PSTR(s) (s).