// I know you're code isn't doing something like this,
// but it shows another drawback of macros vs functions
#include <iostream>
 
#define MACRO_ABS(p) ((p) < 0 ? -(p) : (p))
 
template <typename T>
T function_abs(T p)
{
    return p < 0 ? -p : p;
}
 
int main()
{
    int i = -100;
 
    std::cout << "macro: " << MACRO_ABS(i++) << std::endl;
    std::cout << "i: " << i << std::endl;
 
    i = -100;
 
    std::cout << "function: " << function_abs(i++) << std::endl;
    std::cout << "i: " << i << std::endl;
}

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