diff --git a/paddle/fluid/distributed/collective/reducer.cc b/paddle/fluid/distributed/collective/reducer.cc
index 1438bf1f161ec8..b1e81130728e45 100644
--- a/paddle/fluid/distributed/collective/reducer.cc
+++ b/paddle/fluid/distributed/collective/reducer.cc
@@ -21,8 +21,7 @@
 PD_DECLARE_bool(use_stream_safe_cuda_allocator);
 COMMON_DECLARE_string(allocator_strategy);
 
-namespace paddle {
-namespace distributed {
+namespace paddle::distributed {
 
 static bool IsStreamSafeAllocator() {
   return (FLAGS_allocator_strategy == "auto_growth" &&
@@ -1367,5 +1366,4 @@ std::ostream &operator<<(std::ostream &out, const EagerGroup &group) {
   return out;
 }
 
-}  //  namespace distributed
-}  //  namespace paddle
+}  // namespace paddle::distributed 
diff --git a/paddle/fluid/distributed/fleet_executor/message_service.cc b/paddle/fluid/distributed/fleet_executor/message_service.cc
index d99ca36ee4a482..5862a48182f7bf 100644
--- a/paddle/fluid/distributed/fleet_executor/message_service.cc
+++ b/paddle/fluid/distributed/fleet_executor/message_service.cc
@@ -18,8 +18,7 @@
 #include "paddle/fluid/distributed/fleet_executor/global.h"
 #include "paddle/fluid/distributed/fleet_executor/message_bus.h"
 
-namespace paddle {
-namespace distributed {
+namespace paddle::distributed {
 
 void MessageServiceImpl::ReceiveInterceptorMessage(
     google::protobuf::RpcController* control_base,
@@ -46,6 +45,5 @@ void MessageServiceImpl::IncreaseBarrierCount(
   response->set_rst(true);
 }
 
-}  // namespace distributed
-}  // namespace paddle
+}  // namespace paddle::distributed 
 #endif
diff --git a/paddle/fluid/distributed/ps/service/communicator/communicator.cc b/paddle/fluid/distributed/ps/service/communicator/communicator.cc
index 66a5fb1dd5a07a..e57ec2ef187c80 100644
--- a/paddle/fluid/distributed/ps/service/communicator/communicator.cc
+++ b/paddle/fluid/distributed/ps/service/communicator/communicator.cc
@@ -25,8 +25,7 @@ limitations under the License. */
 #define LEARNING_RATE_DECAY_COUNTER "@LR_DECAY_COUNTER@"
 #define STEP_COUNTER "@PS_STEP_COUNTER@"
 
-namespace paddle {
-namespace distributed {
+namespace paddle::distributed {
 
 using phi::SelectedRows;
 
@@ -1590,5 +1589,4 @@ void FLCommunicator::StartCoordinator(
       new std::thread(&FLCommunicator::SendThreadAsync, this));
 }
 
-}  // namespace distributed
-}  // namespace paddle
+}  // namespace paddle::distributed 
diff --git a/paddle/fluid/framework/fleet/metrics.cc b/paddle/fluid/framework/fleet/metrics.cc
index 82bbd16b483ae2..5bb768529bc493 100644
--- a/paddle/fluid/framework/fleet/metrics.cc
+++ b/paddle/fluid/framework/fleet/metrics.cc
@@ -21,8 +21,7 @@
 #include "paddle/fluid/framework/lod_tensor.h"
 
 #if defined(PADDLE_WITH_PSLIB) || defined(PADDLE_WITH_PSCORE)
-namespace paddle {
-namespace framework {
+namespace paddle::framework {
 
 std::shared_ptr<Metric> Metric::s_instance_ = nullptr;
 
@@ -393,6 +392,5 @@ BasicAucCalculator::WuaucRocData BasicAucCalculator::computeSingleUserAuc(
   return {tp, fp, auc};
 }
 
-}  // namespace framework
-}  // namespace paddle
+}  // namespace paddle::framework 
 #endif
diff --git a/paddle/fluid/framework/ir/embedding_fc_lstm_fuse_pass.cc b/paddle/fluid/framework/ir/embedding_fc_lstm_fuse_pass.cc
index 08d93630eadcdc..4e68d98be13ab5 100644
--- a/paddle/fluid/framework/ir/embedding_fc_lstm_fuse_pass.cc
+++ b/paddle/fluid/framework/ir/embedding_fc_lstm_fuse_pass.cc
@@ -20,9 +20,7 @@
 #include "paddle/fluid/framework/op_version_registry.h"
 #include "paddle/phi/kernels/funcs/blas/blas.h"
 
-namespace paddle {
-namespace framework {
-namespace ir {
+namespace paddle::framework::ir {
 
 static int BuildFusion(Graph* graph,
                        const std::string& name_scope,
@@ -288,9 +286,7 @@ void EmbeddingFCLSTMFusePass::ApplyImpl(ir::Graph* graph) const {
   AddStatis(fusion_count);
 }
 
-}  // namespace ir
-}  // namespace framework
-}  // namespace paddle
+}  // namespace paddle::framework::ir 
 
 REGISTER_PASS(embedding_fc_lstm_fuse_pass,
               paddle::framework::ir::EmbeddingFCLSTMFusePass);
diff --git a/paddle/fluid/framework/ir/fused_continuous_same_ops_pass.cc b/paddle/fluid/framework/ir/fused_continuous_same_ops_pass.cc
index 62b043bf3294b0..ec67c675076a77 100644
--- a/paddle/fluid/framework/ir/fused_continuous_same_ops_pass.cc
+++ b/paddle/fluid/framework/ir/fused_continuous_same_ops_pass.cc
@@ -21,19 +21,16 @@
 
 namespace phi {
 class DenseTensor;
-}  // namespace phi
+}  // namespace phi 
 
-namespace paddle {
-namespace framework {
+namespace paddle::framework {
 class Scope;
-}  // namespace framework
-}  // namespace paddle
+}  // namespace paddle::framework 
 
-namespace paddle {
-namespace framework {
-namespace ir {
+namespace paddle::framework::ir {
 
-namespace patterns {
+}  // namespace paddle::framework::ir 
+namespace paddle::framework::ir::patterns {
 
 struct ContinuousSameOpsPattern : public PatternBase {
   ContinuousSameOpsPattern(PDPattern* pattern,
@@ -85,7 +82,8 @@ ContinuousSameOpsPattern::ContinuousSameOpsPattern(
       .LinksTo({second_out_var_node});
 }
 
-}  // namespace patterns
+}  // namespace paddle::framework::ir::patterns 
+namespace paddle::framework::ir {
 
 /*
 Fused continuous same ops into one.
@@ -221,9 +219,7 @@ void FusedContinuousSameOpsPass::ApplyImpl(ir::Graph* graph) const {
   LOG(INFO) << "Total delete op counts: " << total_delete_op_count;
 }
 
-}  // namespace ir
-}  // namespace framework
-}  // namespace paddle
+}  // namespace paddle::framework::ir 
 
 REGISTER_PASS(fused_continuous_same_ops_pass,
               paddle::framework::ir::FusedContinuousSameOpsPass);
diff --git a/paddle/fluid/framework/ir/fused_feedforward_pass.cc b/paddle/fluid/framework/ir/fused_feedforward_pass.cc
index 0ae23adfc425c8..4f1c51b96b1c42 100644
--- a/paddle/fluid/framework/ir/fused_feedforward_pass.cc
+++ b/paddle/fluid/framework/ir/fused_feedforward_pass.cc
@@ -19,9 +19,7 @@
 #include "paddle/fluid/framework/operator.h"
 #include "paddle/fluid/platform/enforce.h"
 
-namespace paddle {
-namespace framework {
-namespace ir {
+namespace paddle::framework::ir {
 
 void FusedFeedForwardPass::ApplyImpl(ir::Graph *graph) const {
   FusePassBase::Init(scope_name, graph);
@@ -752,9 +750,7 @@ ir::Graph *FusedFeedForwardPass::FusedFeedForwardBwd(
   return graph;
 }
 
-}  // namespace ir
-}  // namespace framework
-}  // namespace paddle
+}  // namespace paddle::framework::ir 
 
 REGISTER_PASS(fused_feedforward_pass,
               paddle::framework::ir::FusedFeedForwardPass);
diff --git a/paddle/fluid/framework/ir/fusion_group/code_generator_helper.cc b/paddle/fluid/framework/ir/fusion_group/code_generator_helper.cc
index 24e5712462b113..9ebe1fdcce309d 100644
--- a/paddle/fluid/framework/ir/fusion_group/code_generator_helper.cc
+++ b/paddle/fluid/framework/ir/fusion_group/code_generator_helper.cc
@@ -19,10 +19,7 @@ limitations under the License. */
 
 #include "paddle/fluid/framework/ir/fusion_group/operation.h"
 
-namespace paddle {
-namespace framework {
-namespace ir {
-namespace fusion_group {
+namespace paddle::framework::ir::fusion_group {
 
 template <typename T>
 static T StringTo(const std::string& str) {
@@ -219,7 +216,4 @@ std::string OperationExpression::GetExpression(
   return ret.str();
 }
 
-}  // namespace fusion_group
-}  // namespace ir
-}  // namespace framework
-}  // namespace paddle
+}  // namespace paddle::framework::ir::fusion_group 
diff --git a/paddle/fluid/framework/ir/memory_optimize_pass/reference_count_pass.cc b/paddle/fluid/framework/ir/memory_optimize_pass/reference_count_pass.cc
index 69d304d0a7c2b0..501ed3fec11c46 100644
--- a/paddle/fluid/framework/ir/memory_optimize_pass/reference_count_pass.cc
+++ b/paddle/fluid/framework/ir/memory_optimize_pass/reference_count_pass.cc
@@ -23,9 +23,7 @@
 #include "paddle/fluid/framework/ir/memory_optimize_pass/reference_count_pass_helper.h"
 #include "paddle/fluid/framework/ir/pass.h"
 
-namespace paddle {
-namespace framework {
-namespace ir {
+namespace paddle::framework::ir {
 
 class Graph;
 
@@ -362,9 +360,7 @@ void ReferenceCountPass::ApplyImpl(ir::Graph *graph) const {
   }
 }
 
-}  // namespace ir
-}  // namespace framework
-}  // namespace paddle
+}  // namespace paddle::framework::ir 
 
 REGISTER_PASS(reference_count_pass, paddle::framework::ir::ReferenceCountPass)
     .RequirePassAttr(paddle::framework::ir::kMemOptVarInfoMapList)
diff --git a/paddle/fluid/framework/ir/onednn/cpu_bfloat16_placement_pass.cc b/paddle/fluid/framework/ir/onednn/cpu_bfloat16_placement_pass.cc
index a07887dafb2767..9adc07d9c14639 100644
--- a/paddle/fluid/framework/ir/onednn/cpu_bfloat16_placement_pass.cc
+++ b/paddle/fluid/framework/ir/onednn/cpu_bfloat16_placement_pass.cc
@@ -21,9 +21,7 @@ limitations under the License. */
 #include "paddle/fluid/platform/onednn_helper.h"
 #include "paddle/utils/string/pretty_log.h"
 
-namespace paddle {
-namespace framework {
-namespace ir {
+namespace paddle::framework::ir {
 
 using string::PrettyLogDetail;
 
@@ -111,9 +109,7 @@ int CPUBfloat16PlacementPass::RemoveUnsupportedOperators(
   return detected_operators;
 }
 
-}  // namespace ir
-}  // namespace framework
-}  // namespace paddle
+}  // namespace paddle::framework::ir 
 
 REGISTER_PASS(cpu_bfloat16_placement_pass,
               paddle::framework::ir::CPUBfloat16PlacementPass)
diff --git a/paddle/fluid/framework/ir/onednn/fc_onednn_pass.cc b/paddle/fluid/framework/ir/onednn/fc_onednn_pass.cc
index 082579428a01a4..62a0f3d20f19d6 100644
--- a/paddle/fluid/framework/ir/onednn/fc_onednn_pass.cc
+++ b/paddle/fluid/framework/ir/onednn/fc_onednn_pass.cc
@@ -17,15 +17,11 @@
 #include "paddle/phi/core/enforce.h"
 #include "paddle/utils/string/pretty_log.h"
 
-namespace paddle {
-namespace framework {
+namespace paddle::framework {
 class OpDesc;
-}  // namespace framework
-}  // namespace paddle
+}  // namespace paddle::framework 
 
-namespace paddle {
-namespace framework {
-namespace ir {
+namespace paddle::framework::ir {
 
 class Graph;
 
@@ -85,8 +81,6 @@ void FCMKLDNNPass::ApplyImpl(ir::Graph* graph) const {
   }
 }
 
-}  // namespace ir
-}  // namespace framework
-}  // namespace paddle
+}  // namespace paddle::framework::ir 
 
 REGISTER_PASS(fc_onednn_pass, paddle::framework::ir::FCMKLDNNPass);
diff --git a/paddle/fluid/framework/ir/preln_layernorm_x_fuse_pass.cc b/paddle/fluid/framework/ir/preln_layernorm_x_fuse_pass.cc
index 5f4c59333f2602..08a576c64fa565 100644
--- a/paddle/fluid/framework/ir/preln_layernorm_x_fuse_pass.cc
+++ b/paddle/fluid/framework/ir/preln_layernorm_x_fuse_pass.cc
@@ -19,18 +19,11 @@ limitations under the License. */
 #include "paddle/fluid/framework/ir/graph_pattern_detector.h"
 #include "paddle/fluid/framework/op_version_registry.h"
 
-namespace paddle {
-namespace framework {
-namespace ir {
+namespace paddle::framework::ir {
 class Node;
-}  // namespace ir
-}  // namespace framework
-}  // namespace paddle
+}  // namespace paddle::framework::ir 
 
-namespace paddle {
-namespace framework {
-namespace ir {
-namespace patterns {
+namespace paddle::framework::ir::patterns {
 
 struct PrelnLayerNormX : public PatternBase {
   PrelnLayerNormX(PDPattern *pattern, const std::string &name_scope)
@@ -86,7 +79,8 @@ void PrelnLayerNormX::operator()(PDNode *x,
       .LinksTo({layer_norm_out_var});
 }
 
-}  // namespace patterns
+}  // namespace paddle::framework::ir::patterns 
+namespace paddle::framework::ir {
 
 int PrelnLayerNormXFusePass::ApplyLayerNormShiftPattern(
     ir::Graph *graph) const {
@@ -253,9 +247,7 @@ void PrelnLayerNormXFusePass::ApplyImpl(ir::Graph *graph) const {
   AddStatis(found_subgraph_count);
 }
 
-}  // namespace ir
-}  // namespace framework
-}  // namespace paddle
+}  // namespace paddle::framework::ir 
 
 REGISTER_PASS(preln_layernorm_x_fuse_pass,
               paddle::framework::ir::PrelnLayerNormXFusePass);
diff --git a/paddle/fluid/framework/ir/seqpool_concat_fuse_pass.cc b/paddle/fluid/framework/ir/seqpool_concat_fuse_pass.cc
index 40519a58d006f9..72e95c5f441500 100644
--- a/paddle/fluid/framework/ir/seqpool_concat_fuse_pass.cc
+++ b/paddle/fluid/framework/ir/seqpool_concat_fuse_pass.cc
@@ -16,19 +16,13 @@
 
 #include <string>
 
-namespace paddle {
-namespace framework {
-namespace ir {
+namespace paddle::framework::ir {
 class Node;
-}  // namespace ir
-}  // namespace framework
-}  // namespace paddle
+}  // namespace paddle::framework::ir 
 
 #define MAX_CONCAT_INPUTS 200
 
-namespace paddle {
-namespace framework {
-namespace ir {
+namespace paddle::framework::ir {
 
 PDNode* BuildSeqPoolConcatPattern(PDPattern* pattern,
                                   const std::string& name_scope,
@@ -217,9 +211,7 @@ void SeqPoolConcatFusePass::ApplyImpl(ir::Graph* graph) const {
   AddStatis(fusion_count);
 }
 
-}  // namespace ir
-}  // namespace framework
-}  // namespace paddle
+}  // namespace paddle::framework::ir 
 
 REGISTER_PASS(seqpool_concat_fuse_pass,
               paddle::framework::ir::SeqPoolConcatFusePass);
diff --git a/paddle/fluid/framework/ir/sync_batch_norm_pass.cc b/paddle/fluid/framework/ir/sync_batch_norm_pass.cc
index 828418597e623a..5f5a032f6c5c82 100644
--- a/paddle/fluid/framework/ir/sync_batch_norm_pass.cc
+++ b/paddle/fluid/framework/ir/sync_batch_norm_pass.cc
@@ -15,9 +15,7 @@ limitations under the License. */
 #include "glog/logging.h"
 #include "paddle/fluid/framework/ir/pass.h"
 
-namespace paddle {
-namespace framework {
-namespace ir {
+namespace paddle::framework::ir {
 
 class Graph;
 
@@ -43,8 +41,6 @@ class SyncBatchNormPass : public Pass {
     }
   }
 };
-}  // namespace ir
-}  // namespace framework
-}  // namespace paddle
+}  // namespace paddle::framework::ir 
 
 REGISTER_PASS(sync_batch_norm_pass, paddle::framework::ir::SyncBatchNormPass);
diff --git a/paddle/fluid/framework/new_executor/garbage_collector/fast_garbage_collector.cc b/paddle/fluid/framework/new_executor/garbage_collector/fast_garbage_collector.cc
index e9df08d4698e28..9264e5fc92f7fd 100644
--- a/paddle/fluid/framework/new_executor/garbage_collector/fast_garbage_collector.cc
+++ b/paddle/fluid/framework/new_executor/garbage_collector/fast_garbage_collector.cc
@@ -14,8 +14,7 @@
 
 #include "paddle/fluid/framework/new_executor/garbage_collector/fast_garbage_collector.h"
 
-namespace paddle {
-namespace framework {
+namespace paddle::framework {
 
 void InterpreterCoreFastGarbageCollector::Add(Variable* var,
                                               const Instruction&) {
@@ -102,5 +101,4 @@ void InterpreterCoreFastGarbageCollector::Add(Garbage garbage) {
   }
 }
 
-}  // namespace framework
-}  // namespace paddle
+}  // namespace paddle::framework 
diff --git a/paddle/fluid/framework/op_registry.cc b/paddle/fluid/framework/op_registry.cc
index ca1e1b5296d7bc..d4a993b53d9b6a 100644
--- a/paddle/fluid/framework/op_registry.cc
+++ b/paddle/fluid/framework/op_registry.cc
@@ -17,8 +17,7 @@ limitations under the License. */
 
 #include "glog/logging.h"
 
-namespace paddle {
-namespace framework {
+namespace paddle::framework {
 
 std::unique_ptr<OperatorBase> OpRegistry::CreateOp(
     const std::string& type,
@@ -140,5 +139,4 @@ std::unique_ptr<OperatorBase> OpRegistry::CreateOp(const OpDesc& op_desc) {
   return op;
 }
 
-}  // namespace framework
-}  // namespace paddle
+}  // namespace paddle::framework 
diff --git a/paddle/fluid/imperative/heter_ccl_context.cc b/paddle/fluid/imperative/heter_ccl_context.cc
index 37929dc6e9c8f6..d63f416f1db8f6 100644
--- a/paddle/fluid/imperative/heter_ccl_context.cc
+++ b/paddle/fluid/imperative/heter_ccl_context.cc
@@ -27,14 +27,11 @@
 #include "paddle/utils/string/split.h"
 #include "paddle/utils/string/string_helper.h"
 
-namespace paddle {
-namespace framework {
+namespace paddle::framework {
 class Variable;
-}  // namespace framework
-}  // namespace paddle
+}  // namespace paddle::framework 
 
-namespace paddle {
-namespace imperative {
+namespace paddle::imperative {
 
 HeterParallelContext::HeterParallelContext(const ParallelStrategy &strategy,
                                            const int &device_id)
@@ -196,5 +193,4 @@ void HeterParallelContext::SynchronizeCompute() {
   node_parallel_ctx_->SynchronizeCompute();
 }
 
-}  //  namespace imperative
-}  //  namespace paddle
+}  // namespace paddle::imperative 
diff --git a/paddle/fluid/imperative/reducer.cc b/paddle/fluid/imperative/reducer.cc
index e2a2917e52803f..cbf22de94a7d78 100644
--- a/paddle/fluid/imperative/reducer.cc
+++ b/paddle/fluid/imperative/reducer.cc
@@ -26,8 +26,7 @@
 #endif
 #include "paddle/phi/core/dense_tensor.h"
 #include "paddle/utils/string/string_helper.h"
-namespace paddle {
-namespace imperative {
+namespace paddle::imperative {
 
 #if defined(PADDLE_WITH_NCCL) || defined(PADDLE_WITH_RCCL) ||     \
     defined(PADDLE_WITH_XPU_BKCL) || defined(PADDLE_WITH_GLOO) || \
@@ -1160,5 +1159,4 @@ std::vector<std::vector<size_t>> AssignGroupBySize(
 }
 #endif
 
-}  // namespace imperative
-}  // namespace paddle
+}  // namespace paddle::imperative 
diff --git a/paddle/fluid/inference/analysis/passes/convert_to_mixed_precision.cc b/paddle/fluid/inference/analysis/passes/convert_to_mixed_precision.cc
index d7061133070094..a3c531cb114767 100644
--- a/paddle/fluid/inference/analysis/passes/convert_to_mixed_precision.cc
+++ b/paddle/fluid/inference/analysis/passes/convert_to_mixed_precision.cc
@@ -22,9 +22,7 @@
 #include "paddle/fluid/inference/io.h"
 #include "paddle/phi/common/backend.h"
 
-namespace paddle {
-namespace inference {
-namespace analysis {
+namespace paddle::inference::analysis {
 
 ConvertToMixedPrecisionPass::ConvertToMixedPrecisionPass(
     const std::string& model_file,
@@ -242,6 +240,4 @@ void ConvertToMixedPrecision(
   pass.Run();
 }
 
-}  // namespace analysis
-}  // namespace inference
-}  // namespace paddle
+}  // namespace paddle::inference::analysis 
diff --git a/paddle/fluid/inference/tensorrt/convert/multihead_matmul_roformer_op.cc b/paddle/fluid/inference/tensorrt/convert/multihead_matmul_roformer_op.cc
index e65dbd4832ff55..f5f48c76e8cbb9 100644
--- a/paddle/fluid/inference/tensorrt/convert/multihead_matmul_roformer_op.cc
+++ b/paddle/fluid/inference/tensorrt/convert/multihead_matmul_roformer_op.cc
@@ -15,9 +15,7 @@ limitations under the License. */
 #include "paddle/fluid/inference/tensorrt/convert/op_converter.h"
 #include "paddle/fluid/inference/tensorrt/plugin/multihead_matmul_roformer_plugin.h"
 
-namespace paddle {
-namespace inference {
-namespace tensorrt {
+namespace paddle::inference::tensorrt {
 
 class MultiheadMatMulRoformerOpConverter : public OpConverter {
  public:
@@ -245,9 +243,7 @@ class MultiheadMatMulRoformerOpConverter : public OpConverter {
   }
 };
 
-}  // namespace tensorrt
-}  // namespace inference
-}  // namespace paddle
+}  // namespace paddle::inference::tensorrt 
 
 REGISTER_TRT_OP_CONVERTER(multihead_matmul_roformer,
                           MultiheadMatMulRoformerOpConverter);
diff --git a/paddle/fluid/inference/tensorrt/convert/preln_layernorm_shift_partition_op.cc b/paddle/fluid/inference/tensorrt/convert/preln_layernorm_shift_partition_op.cc
index 6017edecaaa58a..3a981d6194c098 100644
--- a/paddle/fluid/inference/tensorrt/convert/preln_layernorm_shift_partition_op.cc
+++ b/paddle/fluid/inference/tensorrt/convert/preln_layernorm_shift_partition_op.cc
@@ -15,9 +15,7 @@ limitations under the License. */
 #include "paddle/fluid/inference/tensorrt/convert/op_converter.h"
 #include "paddle/fluid/inference/tensorrt/plugin/prelnlayernorm_shift_partition_op.h"
 
-namespace paddle {
-namespace inference {
-namespace tensorrt {
+namespace paddle::inference::tensorrt {
 
 class PrelnLayerNormShiftPartitionOpConverter : public OpConverter {
  public:
@@ -83,9 +81,7 @@ class PrelnLayerNormShiftPartitionOpConverter : public OpConverter {
   }
 };
 
-}  // namespace tensorrt
-}  // namespace inference
-}  // namespace paddle
+}  // namespace paddle::inference::tensorrt 
 
 REGISTER_TRT_OP_CONVERTER(preln_layernorm_shift_partition,
                           PrelnLayerNormShiftPartitionOpConverter);
diff --git a/paddle/fluid/inference/tensorrt/convert/yolo_box_op.cc b/paddle/fluid/inference/tensorrt/convert/yolo_box_op.cc
index 3ed413a913fd07..8ae9aa4915e1b1 100644
--- a/paddle/fluid/inference/tensorrt/convert/yolo_box_op.cc
+++ b/paddle/fluid/inference/tensorrt/convert/yolo_box_op.cc
@@ -14,9 +14,7 @@ limitations under the License. */
 #include "paddle/fluid/inference/tensorrt/convert/op_converter.h"
 #include "paddle/fluid/inference/tensorrt/plugin/yolo_box_op_plugin.h"
 
-namespace paddle {
-namespace inference {
-namespace tensorrt {
+namespace paddle::inference::tensorrt {
 
 class YoloBoxOpConverter : public OpConverter {
  public:
@@ -80,8 +78,6 @@ class YoloBoxOpConverter : public OpConverter {
   }
 };
 
-}  // namespace tensorrt
-}  // namespace inference
-}  // namespace paddle
+}  // namespace paddle::inference::tensorrt 
 
 REGISTER_TRT_OP_CONVERTER(yolo_box, YoloBoxOpConverter);
diff --git a/paddle/fluid/inference/utils/io_utils.cc b/paddle/fluid/inference/utils/io_utils.cc
index db007d269b8975..d60e9ab56fd6ef 100644
--- a/paddle/fluid/inference/utils/io_utils.cc
+++ b/paddle/fluid/inference/utils/io_utils.cc
@@ -23,8 +23,7 @@
 #include "paddle/fluid/inference/analysis/helper.h"
 #include "paddle/fluid/inference/utils/shape_range_info.pb.h"
 
-namespace paddle {
-namespace inference {
+namespace paddle::inference {
 
 // =========================================================
 //       Item        |        Type       |      Bytes
@@ -344,5 +343,4 @@ void UpdateShapeRangeInfo(
   inference::SerializeShapeRangeInfo(path, shape_range_infos);
 }
 
-}  // namespace inference
-}  // namespace paddle
+}  // namespace paddle::inference 
diff --git a/paddle/fluid/jit/engine/predictor_engine.cc b/paddle/fluid/jit/engine/predictor_engine.cc
index a753adc51a5408..c96922c7d2fbc6 100644
--- a/paddle/fluid/jit/engine/predictor_engine.cc
+++ b/paddle/fluid/jit/engine/predictor_engine.cc
@@ -19,8 +19,7 @@
 #include "paddle/fluid/jit/function_utils.h"
 #include "paddle/fluid/platform/device_context.h"
 
-namespace paddle {
-namespace jit {
+namespace paddle::jit {
 
 PredictorEngine::PredictorEngine(
     const std::shared_ptr<FunctionInfo> &info,
@@ -84,5 +83,4 @@ std::vector<DenseTensor> PredictorEngine::operator()(
   return utils::ToDenseTensors(this->operator()(utils::ToTensors(inputs)));
 }
 
-}  // namespace jit
-}  // namespace paddle
+}  // namespace paddle::jit 
diff --git a/paddle/fluid/jit/serializer.cc b/paddle/fluid/jit/serializer.cc
index 24bcf03a764385..8a81b3c729871c 100644
--- a/paddle/fluid/jit/serializer.cc
+++ b/paddle/fluid/jit/serializer.cc
@@ -29,8 +29,7 @@
 
 COMMON_DECLARE_string(jit_engine_type);
 
-namespace paddle {
-namespace jit {
+namespace paddle::jit {
 
 using FunctionInfoMap =
     std::unordered_map<std::string, std::shared_ptr<FunctionInfo>>;
@@ -138,5 +137,4 @@ Layer Load(const std::string& file_path, const phi::Place& place) {
   return deserializer(file_path, place);
 }
 
-}  // namespace jit
-}  // namespace paddle
+}  // namespace paddle::jit 
diff --git a/paddle/fluid/memory/allocation/virtual_memory_auto_growth_best_fit_allocator.cc b/paddle/fluid/memory/allocation/virtual_memory_auto_growth_best_fit_allocator.cc
index 52399df8ce5ff3..37dc216002dcd0 100644
--- a/paddle/fluid/memory/allocation/virtual_memory_auto_growth_best_fit_allocator.cc
+++ b/paddle/fluid/memory/allocation/virtual_memory_auto_growth_best_fit_allocator.cc
@@ -18,9 +18,7 @@
 
 #include "paddle/fluid/memory/allocation/aligned_allocator.h"
 
-namespace paddle {
-namespace memory {
-namespace allocation {
+namespace paddle::memory::allocation {
 
 bool NeedSplit(size_t block_size, size_t alignment, size_t alloc_size) {
   return block_size > (alloc_size * 2) || (block_size - alloc_size) > alignment;
@@ -252,6 +250,4 @@ phi::Allocation *VirtualMemoryAutoGrowthBestFitAllocator::AllocFromFreeBlocks(
   return nullptr;
 }
 
-}  // namespace allocation
-}  // namespace memory
-}  // namespace paddle
+}  // namespace paddle::memory::allocation 
diff --git a/paddle/fluid/operators/collective/alltoall_op.cc b/paddle/fluid/operators/collective/alltoall_op.cc
index dd7b6f166d7aed..879f1c082372db 100644
--- a/paddle/fluid/operators/collective/alltoall_op.cc
+++ b/paddle/fluid/operators/collective/alltoall_op.cc
@@ -14,8 +14,7 @@ limitations under the License. */
 
 #include "paddle/fluid/operators/collective/alltoall_op.h"
 
-namespace paddle {
-namespace operators {
+namespace paddle::operators {
 
 class AllToAllBaseOp : public framework::OperatorWithKernel {
  public:
@@ -61,8 +60,7 @@ Scatter tensors from all participators to all participators.
   }
 };
 
-}  // namespace operators
-}  // namespace paddle
+}  // namespace paddle::operators 
 
 namespace ops = paddle::operators;
 
diff --git a/paddle/fluid/operators/collective/c_split_op.cc b/paddle/fluid/operators/collective/c_split_op.cc
index b0c998ff79710e..a0244e045379a0 100644
--- a/paddle/fluid/operators/collective/c_split_op.cc
+++ b/paddle/fluid/operators/collective/c_split_op.cc
@@ -14,8 +14,7 @@ limitations under the License. */
 
 #include "paddle/fluid/operators/collective/c_split_op.h"
 
-namespace paddle {
-namespace operators {
+namespace paddle::operators {
 
 class CSplitOp : public framework::OperatorWithKernel {
  public:
@@ -109,8 +108,7 @@ Split the tensor evenly according to its rank.
   }
 };
 
-}  // namespace operators
-}  // namespace paddle
+}  // namespace paddle::operators 
 
 namespace ops = paddle::operators;
 
diff --git a/paddle/fluid/operators/fused/fused_adam_op.cc b/paddle/fluid/operators/fused/fused_adam_op.cc
index d786dbd7c2728f..9fccf1cb810316 100644
--- a/paddle/fluid/operators/fused/fused_adam_op.cc
+++ b/paddle/fluid/operators/fused/fused_adam_op.cc
@@ -17,8 +17,7 @@
 #include "paddle/phi/core/infermeta_utils.h"
 #include "paddle/phi/infermeta/multiary.h"
 
-namespace paddle {
-namespace operators {
+namespace paddle::operators {
 
 using Tensor = phi::DenseTensor;
 
@@ -155,8 +154,7 @@ param\_out & = param - learning\_rate * (\frac{moment\_1}{\sqrt{moment\_2} + \ep
   }
 };
 
-}  // namespace operators
-}  // namespace paddle
+}  // namespace paddle::operators 
 
 namespace ops = paddle::operators;
 DECLARE_INFER_SHAPE_FUNCTOR(fused_adam,
diff --git a/paddle/fluid/operators/fused/fused_matmul_op.cc b/paddle/fluid/operators/fused/fused_matmul_op.cc
index 93d79d677f8a5a..0e9c34ba8aeed8 100644
--- a/paddle/fluid/operators/fused/fused_matmul_op.cc
+++ b/paddle/fluid/operators/fused/fused_matmul_op.cc
@@ -20,8 +20,7 @@
 #include "paddle/phi/core/infermeta_utils.h"
 #include "paddle/phi/infermeta/binary.h"
 
-namespace paddle {
-namespace operators {
+namespace paddle::operators {
 
 static std::vector<int64_t> GetInputShape(phi::DDim dim,
                                           std::vector<int> shape,
@@ -237,8 +236,7 @@ class FusedMatmulOpMaker : public framework::OpProtoAndCheckerMaker {
   }
 };
 
-}  // namespace operators
-}  // namespace paddle
+}  // namespace paddle::operators 
 
 namespace ops = paddle::operators;
 DECLARE_INFER_SHAPE_FUNCTOR(fused_matmul,
diff --git a/paddle/fluid/operators/pull_gpups_sparse_op.cc b/paddle/fluid/operators/pull_gpups_sparse_op.cc
index 1ec27120cc51fd..a283d326723ea8 100644
--- a/paddle/fluid/operators/pull_gpups_sparse_op.cc
+++ b/paddle/fluid/operators/pull_gpups_sparse_op.cc
@@ -14,8 +14,7 @@
 
 #include "paddle/fluid/operators/pull_gpups_sparse_op.h"
 
-namespace paddle {
-namespace operators {
+namespace paddle::operators {
 
 class PullGpuPSSparseOp : public framework::OperatorWithKernel {
  public:
@@ -136,8 +135,7 @@ class PushGpuPSSparseOp : public framework::OperatorWithKernel {
                           ctx.GetPlace());
   }
 };
-}  // namespace operators
-}  // namespace paddle
+}  // namespace paddle::operators 
 
 namespace ops = paddle::operators;
 REGISTER_OPERATOR(pull_gpups_sparse,
diff --git a/paddle/fluid/operators/py_func_op.cc b/paddle/fluid/operators/py_func_op.cc
index 140f415e39d40c..fcd788c37e6603 100644
--- a/paddle/fluid/operators/py_func_op.cc
+++ b/paddle/fluid/operators/py_func_op.cc
@@ -24,8 +24,7 @@
 
 #include "paddle/fluid/framework/op_registry.h"
 
-namespace paddle {
-namespace operators {
+namespace paddle::operators {
 
 namespace py = ::pybind11;
 
@@ -348,8 +347,7 @@ class PyFuncOp : public framework::OperatorBase {
   }
 };
 
-}  // namespace operators
-}  // namespace paddle
+}  // namespace paddle::operators 
 
 namespace ops = paddle::operators;
 
diff --git a/paddle/fluid/operators/rrelu_op.cc b/paddle/fluid/operators/rrelu_op.cc
index 3111ad4e5015d8..1f84851221ebc6 100644
--- a/paddle/fluid/operators/rrelu_op.cc
+++ b/paddle/fluid/operators/rrelu_op.cc
@@ -19,8 +19,7 @@ limitations under the License. */
 #include "paddle/fluid/framework/op_registry.h"
 #include "paddle/phi/infermeta/unary.h"
 
-namespace paddle {
-namespace operators {
+namespace paddle::operators {
 
 class RReluOp : public framework::OperatorWithKernel {
  public:
@@ -110,8 +109,7 @@ class RReluGradOpMaker : public framework::SingleGradOpMaker<T> {
   }
 };
 
-}  // namespace operators
-}  // namespace paddle
+}  // namespace paddle::operators 
 
 namespace ops = paddle::operators;
 DECLARE_INFER_SHAPE_FUNCTOR(rrelu,
diff --git a/paddle/fluid/pir/dialect/operator/ir/manual_onednn_op.cc b/paddle/fluid/pir/dialect/operator/ir/manual_onednn_op.cc
index 7ee35911589cd4..4dee247fd55415 100644
--- a/paddle/fluid/pir/dialect/operator/ir/manual_onednn_op.cc
+++ b/paddle/fluid/pir/dialect/operator/ir/manual_onednn_op.cc
@@ -43,9 +43,7 @@ paddle::onednn::dialect::ExpandOp
 #include "paddle/pir/include/core/ir_context.h"
 #include "paddle/pir/include/core/op_base.h"
 
-namespace paddle {
-namespace onednn {
-namespace dialect {
+namespace paddle::onednn::dialect {
 
 const char* ExpandOp::attributes_name[1] = {"mkldnn_data_type"};  // NOLINT
 
@@ -358,9 +356,7 @@ bool ExpandOp::InferSymbolicShape(
   return true;
 }
 
-}  // namespace dialect
-}  // namespace onednn
-}  // namespace paddle
+}  // namespace paddle::onednn::dialect 
 
 IR_DEFINE_EXPLICIT_TYPE_ID(paddle::onednn::dialect::ExpandOp)
 #endif
diff --git a/paddle/fluid/platform/device_event_base.cc b/paddle/fluid/platform/device_event_base.cc
index 6079691fe873cb..429cc6657885cb 100644
--- a/paddle/fluid/platform/device_event_base.cc
+++ b/paddle/fluid/platform/device_event_base.cc
@@ -17,8 +17,7 @@
 #include "paddle/fluid/platform/device_event_cpu.h"
 #include "paddle/fluid/platform/event.h"
 
-namespace paddle {
-namespace platform {
+namespace paddle::platform {
 
 EventCreateFunction DeviceEvent::event_creator_[MaxDeviceTypes];   // NOLINT
 EventRecordFunction DeviceEvent::event_recorder_[MaxDeviceTypes];  // NOLINT
@@ -130,8 +129,7 @@ void EventResetCPU(const DeviceEvent* event) {
   wrapper->status_ = EventStatus::INITIALIZED;
 }
 
-}  // namespace platform
-}  // namespace paddle
+}  // namespace paddle::platform 
 
 using ::paddle::platform::kCPU;
 REGISTER_EVENT_CREATE_FUNCTION(kCPU, paddle::platform::DeviceEventCreateCPU)
diff --git a/paddle/fluid/platform/stream_callback_manager.cc b/paddle/fluid/platform/stream_callback_manager.cc
index 6719a1b6e97bcf..fd4996e3dd122a 100644
--- a/paddle/fluid/platform/stream_callback_manager.cc
+++ b/paddle/fluid/platform/stream_callback_manager.cc
@@ -16,8 +16,7 @@
 
 #include "paddle/fluid/platform/device/device_wrapper.h"
 
-namespace paddle {
-namespace platform {
+namespace paddle::platform {
 
 #ifdef PADDLE_WITH_HIP
 static void StreamCallbackFunc(gpuStream_t stream,
@@ -88,5 +87,4 @@ template class StreamCallbackManager<gpuStream_t>;
 #ifdef PADDLE_WITH_HIP
 template struct StreamCallbackManager<hipStream_t>;
 #endif
-}  // namespace platform
-}  // namespace paddle
+}  // namespace paddle::platform 
diff --git a/paddle/fluid/pybind/bind_cost_model.cc b/paddle/fluid/pybind/bind_cost_model.cc
index 5f99fad6476668..3e13784b74cc47 100644
--- a/paddle/fluid/pybind/bind_cost_model.cc
+++ b/paddle/fluid/pybind/bind_cost_model.cc
@@ -24,8 +24,7 @@ using paddle::framework::CostData;
 using paddle::framework::CostModel;
 using paddle::framework::ProgramDesc;
 
-namespace paddle {
-namespace pybind {
+namespace paddle::pybind {
 
 void BindCostModel(py::module* m) {
   py::class_<CostData>(*m, "CostData")
@@ -56,5 +55,4 @@ void BindCostModel(py::module* m) {
            });
 }
 
-}  // namespace pybind
-}  // namespace paddle
+}  // namespace paddle::pybind 
diff --git a/paddle/fluid/pybind/pir.cc b/paddle/fluid/pybind/pir.cc
index 29c5c764c97534..e49415bac891a8 100644
--- a/paddle/fluid/pybind/pir.cc
+++ b/paddle/fluid/pybind/pir.cc
@@ -121,8 +121,7 @@ using pybind11::return_value_policy;
 COMMON_DECLARE_bool(print_ir);
 COMMON_DECLARE_bool(pir_apply_shape_optimization_pass);
 
-namespace paddle {
-namespace pybind {
+namespace paddle::pybind {
 
 PyTypeObject *g_ir_value_pytype = nullptr;
 
@@ -2498,5 +2497,4 @@ void BindPir(pybind11::module *module) {
   BindIrParser(&ir_module);
 }
 
-}  // namespace pybind
-}  // namespace paddle
+}  // namespace paddle::pybind 
diff --git a/paddle/phi/api/lib/tensor_copy.cc b/paddle/phi/api/lib/tensor_copy.cc
index 4e951570089954..22ecb16f6b2eb6 100644
--- a/paddle/phi/api/lib/tensor_copy.cc
+++ b/paddle/phi/api/lib/tensor_copy.cc
@@ -29,8 +29,7 @@ limitations under the License. */
 #include "paddle/phi/core/distributed/auto_parallel/reshard/reshard_utils.h"
 #include "paddle/phi/infermeta/spmd_rules/rules.h"
 #endif
-namespace paddle {
-namespace experimental {
+namespace paddle::experimental {
 
 void copy(const Tensor& src, const Place& place, bool blocking, Tensor* dst) {
   auto kernel_key_set = ParseKernelKeyByInputArgs(src);
@@ -94,5 +93,4 @@ void copy(const Tensor& src, const Place& place, bool blocking, Tensor* dst) {
   VLOG(6) << "copy finished. ";
 }
 
-}  // namespace experimental
-}  // namespace paddle
+}  // namespace paddle::experimental 
diff --git a/paddle/phi/backends/onednn/axpy_handler.cc b/paddle/phi/backends/onednn/axpy_handler.cc
index 0713ebd1adba79..d7756f69e8f715 100644
--- a/paddle/phi/backends/onednn/axpy_handler.cc
+++ b/paddle/phi/backends/onednn/axpy_handler.cc
@@ -21,8 +21,7 @@
 
 #include "paddle/phi/backends/onednn/onednn_helper.h"
 
-namespace phi {
-namespace funcs {
+namespace phi::funcs {
 
 template <typename T>
 class AXPYHandler {
@@ -146,5 +145,4 @@ void OneDNNAXPYHandler<T>::operator()(const T *x, T *y) {
 template class OneDNNAXPYHandler<float>;
 template class OneDNNAXPYHandler<dtype::bfloat16>;
 
-}  // namespace funcs
-}  // namespace phi
+}  // namespace phi::funcs 
diff --git a/paddle/phi/core/distributed/store/tcp_utils.cc b/paddle/phi/core/distributed/store/tcp_utils.cc
index 64c5424928b9ff..f6f871952c36c8 100644
--- a/paddle/phi/core/distributed/store/tcp_utils.cc
+++ b/paddle/phi/core/distributed/store/tcp_utils.cc
@@ -20,9 +20,7 @@
 
 #include "glog/logging.h"
 
-namespace phi {
-namespace distributed {
-namespace tcputils {
+namespace phi::distributed::tcputils {
 
 std::error_code socket_error() {
 #ifdef _WIN32
@@ -223,6 +221,4 @@ std::string receive_string(SocketType socket) {
   return std::string(v.data(), v.size());
 }
 
-}  // namespace tcputils
-}  // namespace distributed
-}  // namespace phi
+}  // namespace phi::distributed::tcputils 
diff --git a/paddle/phi/kernels/funcs/cross_entropy.cc b/paddle/phi/kernels/funcs/cross_entropy.cc
index cf53e9ea65efcc..3b68238b7b1798 100644
--- a/paddle/phi/kernels/funcs/cross_entropy.cc
+++ b/paddle/phi/kernels/funcs/cross_entropy.cc
@@ -17,8 +17,7 @@ limitations under the License. */
 #include "paddle/phi/backends/cpu/cpu_context.h"
 #include "paddle/phi/core/utils/data_type.h"
 
-namespace phi {
-namespace funcs {
+namespace phi::funcs {
 
 using Tensor = phi::DenseTensor;
 template <typename T,
@@ -124,5 +123,4 @@ void CrossEntropyFunctor<DeviceContext, T>::operator()(
 template class CrossEntropyFunctor<phi::CPUContext, float>;
 template class CrossEntropyFunctor<phi::CPUContext, double>;
 
-}  // namespace funcs
-}  // namespace phi
+}  // namespace phi::funcs 
diff --git a/paddle/phi/kernels/funcs/eigen/scale.cc b/paddle/phi/kernels/funcs/eigen/scale.cc
index b3e5246a572269..9eb1d11527c4a0 100644
--- a/paddle/phi/kernels/funcs/eigen/scale.cc
+++ b/paddle/phi/kernels/funcs/eigen/scale.cc
@@ -16,8 +16,7 @@ limitations under the License. */
 #include "paddle/phi/common/float16.h"
 #include "paddle/phi/kernels/funcs/eigen/eigen_function.h"
 
-namespace phi {
-namespace funcs {
+namespace phi::funcs {
 
 template <typename T>
 struct EigenScale<Eigen::DefaultDevice, T> {
@@ -52,5 +51,4 @@ template struct EigenScale<Eigen::DefaultDevice, int64_t>;
 template struct EigenScale<Eigen::DefaultDevice, dtype::complex<float>>;
 template struct EigenScale<Eigen::DefaultDevice, dtype::complex<double>>;
 
-}  // namespace funcs
-}  // namespace phi
+}  // namespace phi::funcs 
diff --git a/paddle/phi/kernels/funcs/fc_functor.cc b/paddle/phi/kernels/funcs/fc_functor.cc
index 5344a23a64ed3c..88613a29b5353d 100644
--- a/paddle/phi/kernels/funcs/fc_functor.cc
+++ b/paddle/phi/kernels/funcs/fc_functor.cc
@@ -18,8 +18,7 @@ limitations under the License. */
 #include "paddle/phi/kernels/funcs/blas/blas.h"
 #include "paddle/phi/kernels/funcs/jit/kernels.h"
 
-namespace phi {
-namespace funcs {
+namespace phi::funcs {
 
 template <typename DeviceContext, typename T>
 void FCFunctor<DeviceContext, T>::operator()(const DeviceContext& context,
@@ -100,5 +99,4 @@ void FCFunctor<DeviceContext, T>::operator()(const DeviceContext& context,
 template class FCFunctor<CPUContext, float>;
 template class FCFunctor<CPUContext, double>;
 
-}  // namespace funcs
-}  // namespace phi
+}  // namespace phi::funcs 
diff --git a/paddle/phi/kernels/funcs/jit/gen/sgd.cc b/paddle/phi/kernels/funcs/jit/gen/sgd.cc
index 930e7794cf94ff..29035e27c7e35f 100644
--- a/paddle/phi/kernels/funcs/jit/gen/sgd.cc
+++ b/paddle/phi/kernels/funcs/jit/gen/sgd.cc
@@ -19,9 +19,7 @@
 #include "paddle/phi/backends/cpu/cpu_info.h"
 #include "paddle/phi/kernels/funcs/jit/registry.h"
 
-namespace phi {
-namespace jit {
-namespace gen {
+namespace phi::jit::gen {
 
 void SgdJitCode::mainCode(int num_regs) {
   constexpr size_t block_size = sizeof(float) * YMM_FLOAT_BLOCK;
@@ -141,9 +139,7 @@ class SgdCreator : public JitCodeCreator<sgd_attr_t> {
   }
 };
 
-}  // namespace gen
-}  // namespace jit
-}  // namespace phi
+}  // namespace phi::jit::gen 
 
 namespace gen = phi::jit::gen;
 
diff --git a/paddle/phi/kernels/funcs/matrix_solve.cc b/paddle/phi/kernels/funcs/matrix_solve.cc
index 31baedb3c314d0..75cb14763e71c8 100644
--- a/paddle/phi/kernels/funcs/matrix_solve.cc
+++ b/paddle/phi/kernels/funcs/matrix_solve.cc
@@ -14,8 +14,7 @@ limitations under the License. */
 
 #include "paddle/phi/kernels/funcs/matrix_solve.h"
 
-namespace phi {
-namespace funcs {
+namespace phi::funcs {
 
 template <typename Context, typename T>
 void MatrixSolveFunctor<Context, T>::operator()(const Context& dev_ctx,
@@ -28,5 +27,4 @@ void MatrixSolveFunctor<Context, T>::operator()(const Context& dev_ctx,
 template class MatrixSolveFunctor<CPUContext, float>;
 template class MatrixSolveFunctor<CPUContext, double>;
 
-}  // namespace funcs
-}  // namespace phi
+}  // namespace phi::funcs 
diff --git a/paddle/phi/kernels/funcs/tensor_formatter.cc b/paddle/phi/kernels/funcs/tensor_formatter.cc
index 7c4cd28fe20c74..d846daae701c4b 100644
--- a/paddle/phi/kernels/funcs/tensor_formatter.cc
+++ b/paddle/phi/kernels/funcs/tensor_formatter.cc
@@ -20,8 +20,7 @@
 #include "paddle/phi/common/place.h"
 #include "paddle/phi/core/tensor_utils.h"
 
-namespace paddle {
-namespace funcs {
+namespace paddle::funcs {
 
 void TensorFormatter::SetPrintTensorType(bool print_tensor_type) {
   print_tensor_type_ = print_tensor_type;
@@ -162,5 +161,4 @@ template void TensorFormatter::FormatData<phi::dtype::float16>(
 template void TensorFormatter::FormatData<phi::dtype::bfloat16>(
     const phi::DenseTensor& print_tensor, std::stringstream& log_stream);
 
-}  // namespace funcs
-}  // namespace paddle
+}  // namespace paddle::funcs 
diff --git a/paddle/phi/kernels/fusion/cpu/fusion_squared_mat_sub_kernel.cc b/paddle/phi/kernels/fusion/cpu/fusion_squared_mat_sub_kernel.cc
index 4f443645774688..1a5fd750b0ea84 100644
--- a/paddle/phi/kernels/fusion/cpu/fusion_squared_mat_sub_kernel.cc
+++ b/paddle/phi/kernels/fusion/cpu/fusion_squared_mat_sub_kernel.cc
@@ -19,8 +19,7 @@
 #include "paddle/phi/core/tensor_utils.h"
 #include "paddle/phi/kernels/funcs/jit/kernels.h"
 
-namespace phi {
-namespace fusion {
+namespace phi::fusion {
 
 template <typename T, typename Context>
 void FusionSquaredMatSubKernel(const Context& dev_ctx,
@@ -78,8 +77,7 @@ void FusionSquaredMatSubKernel(const Context& dev_ctx,
   vscal(&scalar_t, o_data, o_data, o_numel);
 }
 
-}  // namespace fusion
-}  // namespace phi
+}  // namespace phi::fusion 
 
 PD_REGISTER_KERNEL(fusion_squared_mat_sub,
                    CPU,
diff --git a/paddle/phi/kernels/fusion/onednn/fused_matmul_kernel.cc b/paddle/phi/kernels/fusion/onednn/fused_matmul_kernel.cc
index 34c23e6fc288bf..2e0ec565e7d65d 100644
--- a/paddle/phi/kernels/fusion/onednn/fused_matmul_kernel.cc
+++ b/paddle/phi/kernels/fusion/onednn/fused_matmul_kernel.cc
@@ -20,8 +20,7 @@
 
 using dnnl::memory;
 
-namespace phi {
-namespace fusion {
+namespace phi::fusion {
 
 template <typename XT, typename YT, typename OT>
 class FusedMatmulOneDNNHandler
@@ -599,8 +598,7 @@ void FusedMatmulKernel(const Context &dev_ctx,
   }
 }
 
-}  // namespace fusion
-}  // namespace phi
+}  // namespace phi::fusion 
 
 PD_REGISTER_KERNEL(fused_matmul,
                    OneDNN,
diff --git a/paddle/phi/kernels/selected_rows/activation_kernel.cc b/paddle/phi/kernels/selected_rows/activation_kernel.cc
index 4a27d0763a235c..7a72cf72246d9b 100644
--- a/paddle/phi/kernels/selected_rows/activation_kernel.cc
+++ b/paddle/phi/kernels/selected_rows/activation_kernel.cc
@@ -19,8 +19,7 @@
 #include "paddle/phi/core/kernel_registry.h"
 #include "paddle/phi/kernels/activation_kernel.h"
 
-namespace phi {
-namespace sr {
+namespace phi::sr {
 
 template <typename T, typename Context>
 void SquareKernel(const Context& dev_ctx,
@@ -40,8 +39,7 @@ void SqrtKernel(const Context& dev_ctx,
   phi::SqrtKernel<T, Context>(dev_ctx, x.value(), out->mutable_value());
 }
 
-}  // namespace sr
-}  // namespace phi
+}  // namespace phi::sr 
 
 PD_REGISTER_KERNEL(
     square_sr, CPU, ALL_LAYOUT, phi::sr::SquareKernel, float, double) {}