rework

tests/reacitve.cpp

@@ -0,0 +1,21 @@
+#include <gtest/gtest.h>
+
+#include <autoopt/reactive.hpp>
+
+TEST(Reactive, Simple) {
+  using namespace autoopt;
+
+  source<int> s1(0);
+  source<int> s2(0);
+  source<int> s3(0);
+  transform<int, int, int> t1([](int x, int y) { return x + y; }, s1,s2);
+  transform<int, int, int> t2([](int x, int y) { return x + y; }, s2,s3);
+
+  ASSERT_EQ(t2.get(), 0);
+  ASSERT_TRUE(s1.set(1));
+  ASSERT_EQ(t2.get(), 1);
+  s2.set(2);
+  ASSERT_EQ(t2.get(), 3);
+  s3.set(3);
+  ASSERT_EQ(t2.get(), 6);
+}