What does the F() do exactly?

Projects Programming
32

It seems you found a bug in the Arduino code. Here's the fix. Make the following change to WString.h.

class __FlashStringHelper;
//#define F(string_literal) (reinterpret_cast<__FlashStringHelper *>(PSTR(string_literal)))
#define F(string_literal) (reinterpret_cast<const __FlashStringHelper *>(PSTR(string_literal)))