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* Problem with evaluation order in assignment expression after c++17
@ 2022-08-23 14:37 cyb_yorkin
  0 siblings, 0 replies; only message in thread
From: cyb_yorkin @ 2022-08-23 14:37 UTC (permalink / raw)
  To: gcc-help

Hi all,

After c++17, the standard in section [expr.ass] guarantees "right operand is sequenced before the left operand".
I wrote this code, tested in gcc 12.1.

using namespace std;
int a = 1, b = 1;
int *ptr = &a;

int f(){
    ptr = &b;
    return 9;

int main(){
    *ptr = f();
I assume the program will evaluate function f first (it changed the ptr), and then get address of b from the pointer. After that, store returned value into b.
The output should be "1,9", like clang. but gcc give me "9,1".
You can check this here:

I wonder is that a gcc's bug or am I miss something else in c++ standard.


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2022-08-23 14:37 Problem with evaluation order in assignment expression after c++17 cyb_yorkin

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