feat update

src/sled/futures/future.h

@@ -293,7 +293,7 @@ public:
     {
         Future<T, OtherFailureT> result = Future<T, OtherFailureT>::Create();
         OnSuccess([result](const T &v) mutable noexcept { result.FillSuccess(v); });
-        OnFailure([result, f](const FailureT &failure) noexcept {
+        OnFailure([result, f](const FailureT &failure) mutable noexcept {
             try {
                 result.FillFailure(f(failure));
             } catch (const std::exception &e) {

src/sled/futures/future_test.cc

@@ -126,4 +126,24 @@ TEST_SUITE("future")
         REQUIRE_EQ(f1.Result(), 1);
         REQUIRE_EQ(f2.FailureReason(), "1");
     }
+
+    TEST_CASE("MapFailure")
+    {
+        sled::Future<int, bool> f = false;
+        auto f1                   = f.MapFailure([](bool) { return std::string("error"); });
+        CHECK_EQ(f1.FailureReason(), "error");
+    }
+
+    TEST_CASE("Chain")
+    {
+        sled::Future<int, bool> f = 1;
+        auto f1                   = f.Map([](int i) { return i + 1; })
+                      .FlatMap([](int i) {
+                          sled::Promise<std::string, bool> p;
+                          p.Success(std::to_string(i));
+                          return p.GetFuture();
+                      })
+                      .MapFailure([](bool) { return std::exception(); });
+        CHECK_EQ(f1.Result(), "2");
+    }
 }