Why this C++ recursive template didn't work? -


i found interesting question , decided examine top answer in detail.
asked myself why there needs structure , try rewrote code without it: 

#include <iostream> template <int n> void out(std::ostream& os) {     out<n-1>(os);     os << n << std::endl; }  template <> void out<1>(std::ostream& os){     os << 1 << std::endl; }  int main(){     out<100>(std::cout); }

and tried refactor code. got this:

#include <iostream> template <int n> void out() {     if (n != 1) {         out<n-1>();         std::cout << n << std::endl;     }     else {         std::cout << 1 << std::endl;     } }  int main(){     out<100>(); }

i don't understand why code didn't work.
ideas?

the problem if condition evaluated @ run-time. when instantiation n = 1, doesn't know first block of if statement won't execute. proceeds instantiate out<0> , on. if had static if, possible, it won't happen soon.


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