add is_prime

bin/main.cpp

@@ -7,13 +7,18 @@
 #include "numbers/gcd.hpp"
 #include "numbers/prime_factors.hpp"
 #include "numbers/pow.hpp"
+#include "numbers/is_prime.hpp"
 
 auto main() -> int
 {
   {
-    hack::log()(alg::pow(3.0, 2), alg::pow(3.0, 3));
+    hack::log()(alg::is_prime(2));
     return 1;
   }
+
+  {
+    hack::log()(alg::pow(3.0, 2), alg::pow(3.0, 3));
+  }
   
   {
     std::vector<int> v { 5, 4, 1, 5, 6 };