We all know that the code below is an demo code for call by reference,but not pure call by reference, curious about what pure and impure call by reference is? and which programming language's provide pure call by reference.
#include<stdio.h>
void changeX(int *x){
*x = 90;
}
int main(){
int x = 100;
printf("%d ",x);
changeX(&x);
printf("%d",x);
return 0;
}