[ci] fixed cpplint errors about namespace using-directives (#2927)

src/c_api.cpp

@@ -553,7 +553,23 @@ class Booster {
 
 }  // namespace LightGBM
 
-using namespace LightGBM;
+// explicitly declare symbols from LightGBM namespace
+using LightGBM::AllgatherFunction;
+using LightGBM::Booster;
+using LightGBM::Common::CheckElementsIntervalClosed;
+using LightGBM::Common::RemoveQuotationSymbol;
+using LightGBM::Common::Vector2Ptr;
+using LightGBM::Common::VectorSize;
+using LightGBM::Config;
+using LightGBM::data_size_t;
+using LightGBM::Dataset;
+using LightGBM::DatasetLoader;
+using LightGBM::kZeroThreshold;
+using LightGBM::LGBM_APIHandleException;
+using LightGBM::Log;
+using LightGBM::Network;
+using LightGBM::Random;
+using LightGBM::ReduceScatterFunction;
 
 // some help functions used to convert data
 
@@ -785,10 +801,10 @@ int LGBM_DatasetCreateFromMats(int32_t nmat,
       }
     }
     DatasetLoader loader(config, nullptr, 1, nullptr);
-    ret.reset(loader.CostructFromSampleData(Common::Vector2Ptr<double>(&sample_values).data(),
-                                            Common::Vector2Ptr<int>(&sample_idx).data(),
+    ret.reset(loader.CostructFromSampleData(Vector2Ptr<double>(&sample_values).data(),
+                                            Vector2Ptr<int>(&sample_idx).data(),
                                             ncol,
-                                            Common::VectorSize<double>(sample_values).data(),
+                                            VectorSize<double>(sample_values).data(),
                                             sample_cnt, total_nrow));
   } else {
     ret.reset(new Dataset(total_nrow));
@@ -861,10 +877,10 @@ int LGBM_DatasetCreateFromCSR(const void* indptr,
       }
     }
     DatasetLoader loader(config, nullptr, 1, nullptr);
-    ret.reset(loader.CostructFromSampleData(Common::Vector2Ptr<double>(&sample_values).data(),
-                                            Common::Vector2Ptr<int>(&sample_idx).data(),
+    ret.reset(loader.CostructFromSampleData(Vector2Ptr<double>(&sample_values).data(),
+                                            Vector2Ptr<int>(&sample_idx).data(),
                                             static_cast<int>(num_col),
-                                            Common::VectorSize<double>(sample_values).data(),
+                                            VectorSize<double>(sample_values).data(),
                                             sample_cnt, nrow));
   } else {
     ret.reset(new Dataset(nrow));
@@ -929,10 +945,10 @@ int LGBM_DatasetCreateFromCSRFunc(void* get_row_funptr,
       }
     }
     DatasetLoader loader(config, nullptr, 1, nullptr);
-    ret.reset(loader.CostructFromSampleData(Common::Vector2Ptr<double>(&sample_values).data(),
-                                            Common::Vector2Ptr<int>(&sample_idx).data(),
+    ret.reset(loader.CostructFromSampleData(Vector2Ptr<double>(&sample_values).data(),
+                                            Vector2Ptr<int>(&sample_idx).data(),
                                             static_cast<int>(num_col),
-                                            Common::VectorSize<double>(sample_values).data(),
+                                            VectorSize<double>(sample_values).data(),
                                             sample_cnt, nrow));
   } else {
     ret.reset(new Dataset(nrow));
@@ -1002,10 +1018,10 @@ int LGBM_DatasetCreateFromCSC(const void* col_ptr,
     }
     OMP_THROW_EX();
     DatasetLoader loader(config, nullptr, 1, nullptr);
-    ret.reset(loader.CostructFromSampleData(Common::Vector2Ptr<double>(&sample_values).data(),
-                                            Common::Vector2Ptr<int>(&sample_idx).data(),
+    ret.reset(loader.CostructFromSampleData(Vector2Ptr<double>(&sample_values).data(),
+                                            Vector2Ptr<int>(&sample_idx).data(),
                                             static_cast<int>(sample_values.size()),
-                                            Common::VectorSize<double>(sample_values).data(),
+                                            VectorSize<double>(sample_values).data(),
                                             sample_cnt, nrow));
   } else {
     ret.reset(new Dataset(nrow));
@@ -1063,7 +1079,7 @@ int LGBM_DatasetGetSubset(
   CHECK_GT(num_used_row_indices, 0);
   const int32_t lower = 0;
   const int32_t upper = full_dataset->num_data() - 1;
-  Common::CheckElementsIntervalClosed(used_row_indices, lower, upper, num_used_row_indices, "Used indices of subset");
+  CheckElementsIntervalClosed(used_row_indices, lower, upper, num_used_row_indices, "Used indices of subset");
   if (!std::is_sorted(used_row_indices, used_row_indices + num_used_row_indices)) {
     Log::Fatal("used_row_indices should be sorted in Subset");
   }
@@ -1755,7 +1771,7 @@ int LGBM_NetworkInit(const char* machines,
                      int num_machines) {
   API_BEGIN();
   Config config;
-  config.machines = Common::RemoveQuotationSymbol(std::string(machines));
+  config.machines = RemoveQuotationSymbol(std::string(machines));
   config.local_listen_port = local_listen_port;
   config.num_machines = num_machines;
   config.time_out = listen_time_out;

src/lightgbm_R.cpp

@@ -32,7 +32,9 @@
     return call_state;\
   }
 
-using namespace LightGBM;
+using LightGBM::Common::Join;
+using LightGBM::Common::Split;
+using LightGBM::Log;
 
 LGBM_SE EncodeChar(LGBM_SE dest, const char* src, LGBM_SE buf_len, LGBM_SE actual_len, size_t str_len) {
   if (str_len > INT32_MAX) {
@@ -134,7 +136,7 @@ LGBM_SE LGBM_DatasetSetFeatureNames_R(LGBM_SE handle,
   LGBM_SE feature_names,
   LGBM_SE call_state) {
   R_API_BEGIN();
-  auto vec_names = Common::Split(R_CHAR_PTR(feature_names), '\t');
+  auto vec_names = Split(R_CHAR_PTR(feature_names), '\t');
   std::vector<const char*> vec_sptr;
   int len = static_cast<int>(vec_names.size());
   for (int i = 0; i < len; ++i) {
@@ -163,7 +165,7 @@ LGBM_SE LGBM_DatasetGetFeatureNames_R(LGBM_SE handle,
   CHECK_CALL(LGBM_DatasetGetFeatureNames(R_GET_PTR(handle),
     ptr_names.data(), &out_len));
   CHECK_EQ(len, out_len);
-  auto merge_str = Common::Join<char*>(ptr_names, "\t");
+  auto merge_str = Join<char*>(ptr_names, "\t");
   EncodeChar(feature_names, merge_str.c_str(), buf_len, actual_len, merge_str.size() + 1);
   R_API_END();
 }
@@ -468,7 +470,7 @@ LGBM_SE LGBM_BoosterGetEvalNames_R(LGBM_SE handle,
       ptr_names.data()));
   CHECK_EQ(out_len, len);
   CHECK_GE(reserved_string_size, required_string_size);
-  auto merge_names = Common::Join<char*>(ptr_names, "\t");
+  auto merge_names = Join<char*>(ptr_names, "\t");
   EncodeChar(eval_names, merge_names.c_str(), buf_len, actual_len, merge_names.size() + 1);
   R_API_END();
 }