feat add just,then,traits.h

src/exec/just_test.cc

@@ -1,9 +1,40 @@
-#include "sled/ref_count.h"
 #include <gtest/gtest.h>
-#include <sled/exec/just.h>
+#include <sled/exec/exec.h>
 
-TEST(just, basic)
+struct cout_receiver {
+    template<typename T>
+    void SetValue(T &&val)
+    {
+        // 这个receiver什么都不干，只对收集到的结果输出
+        std::cout << "Result: " << val << '\n';
+    }
+
+    void SetError(std::exception_ptr err) { std::terminate(); }
+
+    void SetStopped() { std::terminate(); }
+};
+
+TEST(Just, basic)
 {
-    sled::just_sender<int> sender = sled::just(1);
-    auto op = connect(sender, sled::cout_receiver{});
+    sled::Just(42).Connect(cout_receiver{}).Start();
+    sled::Just(11).Connect(cout_receiver{}).Start();
+}
+
+TEST(Then, basic)
+{
+    auto s1 = sled::Just(42);
+    auto s2 = sled::Then(s1, [](int x) { return x + 1; });
+    auto s3 = sled::Then(s2, [](int x) { return x + 1; });
+    auto s4 = sled::Then(s3, [](int x) { return x + 1; });
+    s4.Connect(cout_receiver{}).Start();
+}
+
+TEST(SyncWait, basic)
+{
+    auto s1 = sled::Just(42);
+    auto s2 = sled::Then(s1, [](int x) { return x + 1; });
+    auto s3 = sled::Then(s2, [](int x) { return x + 1; });
+    auto s4 = sled::Then(s3, [](int x) { return x + 1; });
+    auto s5 = sled::SyncWait(s4).value();
+    std::cout << "Result: " << s5 << '\n';
 }