fixed floating error

tsung-wei-huang · tsung-wei-huang · commit 853d5df1fc0d · 2018-12-17T17:21:51.000-06:00
diff --git a/taskflow/graph/flow_builder.hpp b/taskflow/graph/flow_builder.hpp
@@ -183,7 +183,7 @@ auto FlowBuilder::parallel_for(I beg, I end, I s, C&& c, size_t g) {
 
   using T = std::decay_t<I>;
 
-  if((s == 0 && beg != end) || (beg < end && s <= 0) || (beg > end && s >=0) ) {
+  if((s == 0) || (beg < end && s <= 0) || (beg > end && s >=0) ) {
     TF_THROW(Error::FLOW_BUILDER, 
       "invalid range [", beg, ", ", end, ") with step size ", s
     );
diff --git a/unittest/taskflow.cpp b/unittest/taskflow.cpp
@@ -386,19 +386,18 @@ TEST_CASE("ParallelForOnIndex" * doctest::timeout(300)) {
     REQUIRE_THROWS(tf.parallel_for(0.0, 10.0, -1.0, [] (auto) {}));
     REQUIRE_THROWS(tf.parallel_for(10.0, 0.0, 0.0, [] (auto) {}));
     REQUIRE_THROWS(tf.parallel_for(10.0, 0.0, 1.0, [] (auto) {}));
+    REQUIRE_THROWS(tf.parallel_for(0, 0, 0, [] (auto) {}));
+    REQUIRE_THROWS(tf.parallel_for(0u, 0u, 0u, [] (auto) {}));
+    REQUIRE_THROWS(tf.parallel_for(0.0, 0.0, 0.0, [] (auto) {}));
     
     // graceful case
     REQUIRE_NOTHROW(tf.parallel_for(0, 0, -1, [] (auto) {}));
     REQUIRE_NOTHROW(tf.parallel_for(0, 0, 1, [] (auto) {}));
-    REQUIRE_NOTHROW(tf.parallel_for(0, 0, 0, [] (auto) {}));
     REQUIRE_NOTHROW(tf.parallel_for(0u, 0u, 1u, [] (auto) {}));
-    REQUIRE_NOTHROW(tf.parallel_for(0u, 0u, 0u, [] (auto) {}));
     REQUIRE_NOTHROW(tf.parallel_for(0.0f, 0.0f, -1.0f, [] (auto) {}));
     REQUIRE_NOTHROW(tf.parallel_for(0.0f, 0.0f, 1.0f, [] (auto) {}));
-    REQUIRE_NOTHROW(tf.parallel_for(0.0f, 0.0f, 0.0f, [] (auto) {}));
     REQUIRE_NOTHROW(tf.parallel_for(0.0, 0.0, -1.0, [] (auto) {}));
     REQUIRE_NOTHROW(tf.parallel_for(0.0, 0.0, 1.0, [] (auto) {}));
-    REQUIRE_NOTHROW(tf.parallel_for(0.0, 0.0, 0.0, [] (auto) {}));
   };
 
   auto positive_integer_step = [] (unsigned num_workers) {
