[C++] Update to address comparator failure in big endian

src/idl_gen_cpp.cpp

@@ -2309,14 +2309,16 @@ class CppGenerator : public BaseGenerator {
         code_ +=
             "  int KeyCompareWithValue(const {{INPUT_TYPE}} *_{{FIELD_NAME}}"
             ") const { ";
-        code_ += "    for (auto i = 0; i < {{FIELD_NAME}}()->size(); i++) {";
-        code_ += "      const auto {{FIELD_NAME}}_l = {{FIELD_NAME}}_[i];";
-        code_ += "      const auto {{FIELD_NAME}}_r = _{{FIELD_NAME}}->Get(i);";
-        code_ += "      if({{FIELD_NAME}}_l != {{FIELD_NAME}}_r) ";
         code_ +=
-            "        return static_cast<int>({{FIELD_NAME}}_l > "
-            "{{FIELD_NAME}}_r)"
-            " - static_cast<int>({{FIELD_NAME}}_l < {{FIELD_NAME}}_r);";
+            "    const {{INPUT_TYPE}} *curr_{{FIELD_NAME}} = {{FIELD_NAME}}();";
+        code_ +=
+            "    for (auto i = 0; i < curr_{{FIELD_NAME}}->size(); i++) {";
+        code_ += "      const auto lhs = curr_{{FIELD_NAME}}->Get(i);";
+        code_ += "      const auto rhs = _{{FIELD_NAME}}->Get(i);";
+        code_ += "      if(lhs != rhs) ";
+        code_ +=
+            "        return static_cast<int>(lhs > rhs)"
+            " - static_cast<int>(lhs < rhs);";
         code_ += "    }";
         code_ += "    return 0;";
       }

tests/key_field/key_field_sample_generated.h

@@ -67,12 +67,13 @@ FLATBUFFERS_MANUALLY_ALIGNED_STRUCT(1) Baz FLATBUFFERS_FINAL_CLASS {
   bool KeyCompareLessThan(const Baz * const o) const {
     return KeyCompareWithValue(o->a()) < 0;
   }
-  int KeyCompareWithValue(const flatbuffers::Array<uint8_t, 4> *_a) const { 
-    for (auto i = 0; i < a()->size(); i++) {
-      const auto a_l = a_[i];
-      const auto a_r = _a->Get(i);
-      if(a_l != a_r) 
-        return static_cast<int>(a_l > a_r) - static_cast<int>(a_l < a_r);
+  int KeyCompareWithValue(const flatbuffers::Array<uint8_t, 4> *_a) const {
+    const flatbuffers::Array<uint8_t, 4> *curr_a = a();
+    for (auto i = 0; i < curr_a->size(); i++) {
+      const auto lhs = curr_a->Get(i);
+      const auto rhs = _a->Get(i);
+      if(lhs != rhs)
+        return static_cast<int>(lhs > rhs) - static_cast<int>(lhs < rhs);
     }
     return 0;
   }
@@ -139,12 +140,13 @@ FLATBUFFERS_MANUALLY_ALIGNED_STRUCT(4) Bar FLATBUFFERS_FINAL_CLASS {
   bool KeyCompareLessThan(const Bar * const o) const {
     return KeyCompareWithValue(o->a()) < 0;
   }
-  int KeyCompareWithValue(const flatbuffers::Array<float, 3> *_a) const { 
-    for (auto i = 0; i < a()->size(); i++) {
-      const auto a_l = a_[i];
-      const auto a_r = _a->Get(i);
-      if(a_l != a_r) 
-        return static_cast<int>(a_l > a_r) - static_cast<int>(a_l < a_r);
+  int KeyCompareWithValue(const flatbuffers::Array<float, 3> *_a) const {
+    const flatbuffers::Array<float, 3> *curr_a = a();
+    for (auto i = 0; i < curr_a->size(); i++) {
+      const auto lhs = curr_a->Get(i);
+      const auto rhs = _a->Get(i);
+      if(lhs != rhs)
+        return static_cast<int>(lhs > rhs) - static_cast<int>(lhs < rhs);
     }
     return 0;
   }

tests/key_field_test.cpp

@@ -24,7 +24,9 @@ void FixedSizedScalarKeyInStructTest() {
   bazs.push_back(Baz(flatbuffers::make_span(test_array3), 2));
   bazs.push_back(Baz(flatbuffers::make_span(test_array4), 3));
   auto baz_vec = fbb.CreateVectorOfSortedStructs(&bazs);
+
   auto test_string = fbb.CreateString("TEST");
+
   float test_float_array1[3] = { 1.5, 2.5, 0 };
   float test_float_array2[3] = { 7.5, 2.5, 0 };
   float test_float_array3[3] = { 1.5, 2.5, -1 };
@@ -36,6 +38,7 @@ void FixedSizedScalarKeyInStructTest() {
   bars.push_back(Bar(flatbuffers::make_span(test_float_array4), 1));
   auto bar_vec = fbb.CreateVectorOfSortedStructs(&bars);
 
+
   auto t = CreateFooTable(fbb, 1, 2, test_string, baz_vec, bar_vec);
   fbb.Finish(t);
 
@@ -45,26 +48,34 @@ void FixedSizedScalarKeyInStructTest() {
   auto sorted_baz_vec = foo_table->d();
   TEST_EQ(sorted_baz_vec->Get(0)->b(), 1);
   TEST_EQ(sorted_baz_vec->Get(3)->b(), 4);
+
+  uint8_t test_array[4];
+  auto* key_array = &flatbuffers::CastToArray(test_array);
+  key_array->CopyFromSpan(flatbuffers::make_span(test_array1));
+
+
   TEST_NOTNULL(
-      sorted_baz_vec->LookupByKey(&flatbuffers::CastToArray(test_array1)));
+      sorted_baz_vec->LookupByKey(key_array));
   TEST_EQ(
-      sorted_baz_vec->LookupByKey(&flatbuffers::CastToArray(test_array1))->b(),
+      sorted_baz_vec->LookupByKey(key_array)->b(),
       4);
   uint8_t array_int[4] = { 7, 2, 3, 0 };
-  TEST_EQ(sorted_baz_vec->LookupByKey(&flatbuffers::CastToArray(array_int)),
+  key_array->CopyFromSpan(flatbuffers::make_span(array_int));
+  TEST_EQ(sorted_baz_vec->LookupByKey(key_array),
           static_cast<const Baz *>(nullptr));
 
   auto sorted_bar_vec = foo_table->e();
   TEST_EQ(sorted_bar_vec->Get(0)->b(), 1);
   TEST_EQ(sorted_bar_vec->Get(3)->b(), 4);
-  TEST_NOTNULL(sorted_bar_vec->LookupByKey(
-      &flatbuffers::CastToArray(test_float_array1)));
-  TEST_EQ(
-      sorted_bar_vec->LookupByKey(&flatbuffers::CastToArray(test_float_array1))
-          ->b(),
-      3);
+
+  float test_float_array[3];
+  auto* key_float_array = &flatbuffers::CastToArray(test_float_array);
+  key_float_array->CopyFromSpan(flatbuffers::make_span(test_float_array1));
+  TEST_NOTNULL(sorted_bar_vec->LookupByKey(key_float_array));
+  TEST_EQ(sorted_bar_vec->LookupByKey(key_float_array)->b(), 3);
   float array_float[3] = { -1, -2, -3 };
-  TEST_EQ(sorted_bar_vec->LookupByKey(&flatbuffers::CastToArray(array_float)),
+  key_float_array->CopyFromSpan(flatbuffers::make_span(array_float));
+  TEST_EQ(sorted_bar_vec->LookupByKey(key_float_array),
           static_cast<const Bar *>(nullptr));
 }