what is the different between "static inline" and "static constexpr" in c++20

Question

How does INLINE and CONSTEXPR works and what is the difference between STATIC INLINE vs STATIC CONSTEXPR in c++20!?

Answer 1

inline: tells compiler to copy the code of this function and paste it inside the function that get called. It used for small functions mostly to avoid many call and jump instructions (at assembly level after compile) but can increase executable size. With some settings of the compiler may not do that everytime, so then can use __forceinline that guarantee will do that everytime.

constexpr: will run at compile-time. In general constexpr can used when you want do something at compile-time.
eg: constexpr int test = 23 * 2 + 10;
In this case compiler will calculate the value of test when compiling and not at runtime.
The same happend with functions. For example it used a lot for compile-time encryptions and hashing. Also if want run a function at compile-time, you need also a #define

Answer 2

Giannis https://stackoverflow.com/questions/45183324/whats-the-difference-between-static-constexpr-and-static-inline-variables-in-c

Answer 3

#include <iostream>

inline int var01 = 123;
constexpr int var02 = 316;

int main(int argc, char *argv[])
{

std::cout << "<consoleStart>" << std::endl;
return 0;
}

/* what is different about these variables!? not functions!
Giannis ???

Answer 4

inline variable? is that even valid?
inline only used for functions as i know

Answer 5

Inline variables are valid in C++! that is why i cannot i understand how i use them??? I read above answers of question, but i can't understand how i use it!!!

Answer 6

Do these variables behave same as functions?