Replaced calls to tensorflow::StringPiece::ToString with std::string conversions.

That is, instances of sp.ToString() are replaced with std::string(sp).

This will allow tensorflow::StringPiece::ToString to be removed, which is necessary before it can be replaced with absl::string_view.

PiperOrigin-RevId: 195126422

19 files changed, 82 insertions, 81 deletions

diff --git a/tensorflow/core/kernels/gpu_utils.h b/tensorflow/core/kernels/gpu_utils.h
index 2f64619afc..c7dbefa0b4 100644
--- a/tensorflow/core/kernels/gpu_utils.h
+++ b/tensorflow/core/kernels/gpu_utils.h
@@ -123,7 +123,8 @@ class AutoTuneMap {
   string GetActionSummary(StringPiece action, const Parameters& params,
                           const Config& config) {
     return strings::Printf("autotune_map %s %s: %s -> (%s)", name_.c_str(),
-                           action.ToString().c_str(), params.ToString().c_str(),
+                           std::string(action).c_str(),
+                           params.ToString().c_str(),
                            config.ToString().c_str());
   }
 
diff --git a/tensorflow/core/kernels/merge_v2_checkpoints_op_test.cc b/tensorflow/core/kernels/merge_v2_checkpoints_op_test.cc
index 3b9e9e9b75..10e468ce46 100644
--- a/tensorflow/core/kernels/merge_v2_checkpoints_op_test.cc
+++ b/tensorflow/core/kernels/merge_v2_checkpoints_op_test.cc
@@ -115,7 +115,7 @@ class MergeV2CheckpointsOpTest : public OpsTestBase {
     for (int i = 0; i < 2; ++i) {
       int directory_found =
           Env::Default()
-              ->IsDirectory(io::Dirname(prefixes[i]).ToString())
+              ->IsDirectory(std::string(io::Dirname(prefixes[i])))
               .code();
       if (delete_old_dirs) {
         EXPECT_EQ(error::NOT_FOUND, directory_found);
diff --git a/tensorflow/core/kernels/remote_fused_graph_execute_utils.cc b/tensorflow/core/kernels/remote_fused_graph_execute_utils.cc
index cc4d9a49a0..194a711d98 100644
--- a/tensorflow/core/kernels/remote_fused_graph_execute_utils.cc
+++ b/tensorflow/core/kernels/remote_fused_graph_execute_utils.cc
@@ -47,7 +47,7 @@ std::unordered_set<string> BuildNodeSetFromNodeNamesAndPorts(
   std::unordered_set<string> retval;
   for (const string& node_name_and_port : node_names_and_ports) {
     const TensorId tid = ParseTensorName(node_name_and_port);
-    retval.emplace(tid.first.ToString());
+    retval.emplace(std::string(tid.first));
   }
   return retval;
 }
@@ -64,7 +64,7 @@ Node* FindMutableNodeByName(const string& name, Graph* graph) {
 const NodeDef* FindNodeDefByName(const string& input,
                                  const GraphDef& graph_def) {
   const TensorId tid = ParseTensorName(input);
-  const string name = tid.first.ToString();
+  const string name = std::string(tid.first);
   for (const NodeDef& node_def : graph_def.node()) {
     if (node_def.name() == name) {
       return &node_def;
@@ -77,7 +77,7 @@ bool IsSameNodeName(const NodeDef& node_def, const string& node_name_and_port,
                     TensorId* tid) {
   CHECK_NOTNULL(tid);
   *tid = ParseTensorName(node_name_and_port);
-  if (node_def.name() == tid->first.ToString()) {
+  if (node_def.name() == tid->first) {
     return true;
   }
   return false;
@@ -326,7 +326,7 @@ RemoteFusedGraphExecuteUtils::GetExecutorBuildRegistry() {
     const string& node_name) {
   for (const std::pair<string, Tensor>& pair : input_tensor_vector) {
     const TensorId tid = ParseTensorName(pair.first);
-    if (node_name == tid.first.ToString()) {
+    if (node_name == tid.first) {
       return true;
     }
   }
@@ -423,7 +423,7 @@ RemoteFusedGraphExecuteUtils::AddOutputTensorShapeTypeByTensorShapeMap(
   std::vector<DataType> data_types;
   std::vector<TensorShape> shapes;
   const TensorId tid = ParseTensorName(name_and_port);
-  const string node_name = tid.first.ToString();
+  const string node_name = std::string(tid.first);
   const int port = tid.second;
   const NodeDef* node_def = FindNodeDefByName(node_name, graph_def);
   CHECK_NOTNULL(node_def);
@@ -522,7 +522,7 @@ RemoteFusedGraphExecuteUtils::GetTensorShapeType(
     const TensorShapeMap& tensor_shape_map, const string& node_name) {
   if (node_name.find(':') != string::npos) {
     const TensorId tid = ParseTensorName(node_name);
-    return GetTensorShapeType(tensor_shape_map, tid.first.ToString(),
+    return GetTensorShapeType(tensor_shape_map, std::string(tid.first),
                               tid.second);
   } else {
     return GetTensorShapeType(tensor_shape_map, node_name, 0);
@@ -570,7 +570,7 @@ RemoteFusedGraphExecuteUtils::BuildRemoteGraphInputsAndOutputsFromProto(
   const TensorId tid = ParseTensorName(name);
   CHECK_EQ(tensor_shape_map->count(name), 0);
   tensor_shape_map->emplace(
-      tid.first.ToString(),
+      std::string(tid.first),
       std::make_pair(tid.second,
                      std::make_pair(tensor.dtype(), tensor.shape())));
 }
@@ -692,7 +692,7 @@ RemoteFusedGraphExecuteUtils::BuildRemoteFusedGraphExecuteOpNode(
   std::vector<NodeBuilder::NodeOut> node_out_list;
   for (const string& input : inputs) {
     const TensorId tid = ParseTensorName(input);
-    Node* node = FindMutableNodeByName(tid.first.ToString(), graph);
+    Node* node = FindMutableNodeByName(std::string(tid.first), graph);
     CHECK_NOTNULL(node);
     node_out_list.emplace_back(node, tid.second);
   }
@@ -848,7 +848,7 @@ RemoteFusedGraphExecuteUtils::BuildRemoteFusedGraphExecuteOpNode(
 
   for (const string& subgraph_input : std::get<1>(cluster)) {
     const TensorId tid = ParseTensorName(subgraph_input);
-    const string subgraph_input_name = tid.first.ToString();
+    const string subgraph_input_name = std::string(tid.first);
     const int subgraph_input_port = tid.second;
     const NodeDef* node_def = FindNodeDefByName(subgraph_input_name, graph_def);
     CHECK_NOTNULL(node_def);
@@ -895,7 +895,7 @@ RemoteFusedGraphExecuteUtils::BuildRemoteFusedGraphExecuteOpNode(
   std::deque<const Node*> queue;
   for (const string& output : border_outputs) {
     const TensorId tid = ParseTensorName(output);
-    const string& output_node_name = tid.first.ToString();
+    const string& output_node_name = std::string(tid.first);
     for (const Node* node : graph.nodes()) {
       if (output_node_name == node->name()) {
         queue.push_back(node);
@@ -916,8 +916,7 @@ RemoteFusedGraphExecuteUtils::BuildRemoteFusedGraphExecuteOpNode(
       bool input_found = false;
       for (const string& input : border_inputs) {
         const TensorId tid = ParseTensorName(input);
-        if (tid.first.ToString() == src_node->name() &&
-            tid.second == src_port) {
+        if (tid.first == src_node->name() && tid.second == src_port) {
           input_found = true;
           border_input_nodes.insert(src_node);
         }
@@ -976,7 +975,7 @@ RemoteFusedGraphExecuteUtils::BuildRemoteFusedGraphExecuteOpNode(
       for (int j = 0; j < border_outputs.size(); ++j) {
         const string& output = border_outputs.at(j);
         const TensorId tid = ParseTensorName(output);
-        const string output_name = tid.first.ToString();
+        const string output_name = std::string(tid.first);
         Node* src_node = edge->src();
         if (src_node != nullptr && src_node->name() == output_name &&
             edge->src_output() == tid.second) {
@@ -996,11 +995,12 @@ RemoteFusedGraphExecuteUtils::BuildRemoteFusedGraphExecuteOpNode(
   // RemoteFusedGraphExecuteOpNode
   for (const string& output : outputs) {
     const TensorId output_tid = ParseTensorName(output);
-    const string output_name = output_tid.first.ToString();
+    const string output_name = std::string(output_tid.first);
     for (size_t i = 0; i < border_outputs.size(); ++i) {
       const TensorId subgraph_output_tid =
           ParseTensorName(border_outputs.at(i));
-      const string& subgraph_output_name = subgraph_output_tid.first.ToString();
+      const string& subgraph_output_name =
+          std::string(subgraph_output_tid.first);
       if (output_name == subgraph_output_name) {
         LOG(INFO) << "As graph output and subgraph output are same, "
                   << "the graph output node is replaced by identity node";
@@ -1435,7 +1435,7 @@ RemoteFusedGraphExecuteUtils::BuildNodeMapFromOpsDefinitions(
     GraphDef* graph_def) {
   const TensorId tid = ParseTensorName(input);
   CHECK_EQ(0, tid.second);
-  const string node_name = tid.first.ToString();
+  const string node_name = std::string(tid.first);
   for (NodeDef& node : *graph_def->mutable_node()) {
     if (node.name() != node_name) {
       continue;
diff --git a/tensorflow/core/kernels/save_restore_v2_ops.cc b/tensorflow/core/kernels/save_restore_v2_ops.cc
index 3acf290ea2..ab4de6c815 100644
--- a/tensorflow/core/kernels/save_restore_v2_ops.cc
+++ b/tensorflow/core/kernels/save_restore_v2_ops.cc
@@ -220,9 +220,9 @@ class MergeV2Checkpoints : public OpKernel {
         context, tensorflow::MergeBundles(env, input_prefixes, merged_prefix));
 
     if (delete_old_dirs_) {
-      const string& merged_dir = io::Dirname(merged_prefix).ToString();
+      const string& merged_dir = std::string(io::Dirname(merged_prefix));
       for (const string& input_prefix : input_prefixes) {
-        const string& dirname = io::Dirname(input_prefix).ToString();
+        const string& dirname = std::string(io::Dirname(input_prefix));
         if (dirname == merged_dir) continue;
         Status status = env->DeleteDir(dirname);
         // For sharded save, only the first delete will go through and all
diff --git a/tensorflow/core/kernels/string_strip_op.cc b/tensorflow/core/kernels/string_strip_op.cc
index ae700f4294..2aeafa28c4 100644
--- a/tensorflow/core/kernels/string_strip_op.cc
+++ b/tensorflow/core/kernels/string_strip_op.cc
@@ -43,7 +43,7 @@ class StringStripOp : public OpKernel {
     for (int64 i = 0; i < input.size(); ++i) {
       StringPiece entry(input(i));
       str_util::RemoveWhitespaceContext(&entry);
-      output(i) = entry.ToString();
+      output(i) = std::string(entry);
     }
   }
 };
diff --git a/tensorflow/core/kernels/tensor_array_ops.cc b/tensorflow/core/kernels/tensor_array_ops.cc
index 7ec26d95e6..ef9748b1aa 100644
--- a/tensorflow/core/kernels/tensor_array_ops.cc
+++ b/tensorflow/core/kernels/tensor_array_ops.cc
@@ -293,7 +293,7 @@ class TensorArrayGradOp : public TensorArrayCreationOp {
                                        resource.name());
       }
       tensor_array_name =
-          StringPiece(resource.name()).substr(container.size()).ToString();
+          std::string(StringPiece(resource.name()).substr(container.size()));
     }
 
     auto output_handle = tensor_array_output_handle->flat<string>();
diff --git a/tensorflow/core/kernels/whole_file_read_ops.cc b/tensorflow/core/kernels/whole_file_read_ops.cc
index 17a39ce29b..ed2bf3e8e2 100644
--- a/tensorflow/core/kernels/whole_file_read_ops.cc
+++ b/tensorflow/core/kernels/whole_file_read_ops.cc
@@ -134,7 +134,7 @@ class WriteFileOp : public OpKernel {
                     "Contents tensor must be scalar, but had shape: ",
                     contents_input->shape().DebugString()));
     const string& filename = filename_input->scalar<string>()();
-    const string dir = io::Dirname(filename).ToString();
+    const string dir = std::string(io::Dirname(filename));
     if (!context->env()->FileExists(dir).ok()) {
       OP_REQUIRES_OK(context, context->env()->RecursivelyCreateDir(dir));
     }
diff --git a/tensorflow/core/lib/strings/numbers.h b/tensorflow/core/lib/strings/numbers.h
index e9add42849..9cb56415cb 100644
--- a/tensorflow/core/lib/strings/numbers.h
+++ b/tensorflow/core/lib/strings/numbers.h
@@ -140,11 +140,11 @@ inline bool ProtoParseNumeric(StringPiece s, uint64* value) {
 }
 
 inline bool ProtoParseNumeric(StringPiece s, float* value) {
-  return safe_strtof(s.ToString().c_str(), value);
+  return safe_strtof(std::string(s).c_str(), value);
 }
 
 inline bool ProtoParseNumeric(StringPiece s, double* value) {
-  return safe_strtod(s.ToString().c_str(), value);
+  return safe_strtod(std::string(s).c_str(), value);
 }
 
 // Convert strings to number of type T.
diff --git a/tensorflow/core/lib/strings/scanner_test.cc b/tensorflow/core/lib/strings/scanner_test.cc
index 55ff3405c3..b0f568a03e 100644
--- a/tensorflow/core/lib/strings/scanner_test.cc
+++ b/tensorflow/core/lib/strings/scanner_test.cc
@@ -42,24 +42,24 @@ TEST_F(ScannerTest, Any) {
                   .Any(Scanner::DIGIT)
                   .Any(Scanner::LETTER)
                   .GetResult(&remaining, &match));
-  EXPECT_EQ("   horse", match.ToString());
-  EXPECT_EQ("0123", remaining.ToString());
+  EXPECT_EQ("   horse", match);
+  EXPECT_EQ("0123", remaining);
 
   EXPECT_TRUE(Scanner("")
                   .Any(Scanner::SPACE)
                   .Any(Scanner::DIGIT)
                   .Any(Scanner::LETTER)
                   .GetResult(&remaining, &match));
-  EXPECT_EQ("", remaining.ToString());
-  EXPECT_EQ("", match.ToString());
+  EXPECT_EQ("", remaining);
+  EXPECT_EQ("", match);
 
   EXPECT_TRUE(Scanner("----")
                   .Any(Scanner::SPACE)
                   .Any(Scanner::DIGIT)
                   .Any(Scanner::LETTER)
                   .GetResult(&remaining, &match));
-  EXPECT_EQ("----", remaining.ToString());
-  EXPECT_EQ("", match.ToString());
+  EXPECT_EQ("----", remaining);
+  EXPECT_EQ("", match);
 }
 
 TEST_F(ScannerTest, AnySpace) {
@@ -69,8 +69,8 @@ TEST_F(ScannerTest, AnySpace) {
                   .One(Scanner::LETTER)
                   .AnySpace()
                   .GetResult(&remaining, &match));
-  EXPECT_EQ("  a ", match.ToString());
-  EXPECT_EQ("b ", remaining.ToString());
+  EXPECT_EQ("  a ", match);
+  EXPECT_EQ("b ", remaining);
 }
 
 TEST_F(ScannerTest, AnyEscapedNewline) {
@@ -143,8 +143,8 @@ TEST_F(ScannerTest, ScanUntil) {
                   .ScanUntil('\'')
                   .OneLiteral("'")
                   .GetResult(&remaining, &match));
-  EXPECT_EQ(R"( \\'rest)", remaining.ToString());
-  EXPECT_EQ(R"(' \1 \2 \3 \')", match.ToString());
+  EXPECT_EQ(R"( \\'rest)", remaining);
+  EXPECT_EQ(R"(' \1 \2 \3 \')", match);
 
   // The "scan until" character is not present.
   remaining = match = "unset";
@@ -152,15 +152,15 @@ TEST_F(ScannerTest, ScanUntil) {
                    .OneLiteral("'")
                    .ScanUntil('\'')
                    .GetResult(&remaining, &match));
-  EXPECT_EQ("unset", remaining.ToString());
-  EXPECT_EQ("unset", match.ToString());
+  EXPECT_EQ("unset", remaining);
+  EXPECT_EQ("unset", match);
 
   // Scan until an escape character.
   remaining = match = "";
   EXPECT_TRUE(
       Scanner(R"(123\456)").ScanUntil('\\').GetResult(&remaining, &match));
-  EXPECT_EQ(R"(\456)", remaining.ToString());
-  EXPECT_EQ("123", match.ToString());
+  EXPECT_EQ(R"(\456)", remaining);
+  EXPECT_EQ("123", match);
 }
 
 TEST_F(ScannerTest, ScanEscapedUntil) {
@@ -170,8 +170,8 @@ TEST_F(ScannerTest, ScanEscapedUntil) {
                   .ScanEscapedUntil('\'')
                   .OneLiteral("'")
                   .GetResult(&remaining, &match));
-  EXPECT_EQ("rest", remaining.ToString());
-  EXPECT_EQ(R"(' \1 \2 \3 \' \\')", match.ToString());
+  EXPECT_EQ("rest", remaining);
+  EXPECT_EQ(R"(' \1 \2 \3 \' \\')", match);
 
   // The "scan until" character is not present.
   remaining = match = "unset";
@@ -179,27 +179,27 @@ TEST_F(ScannerTest, ScanEscapedUntil) {
                    .OneLiteral("'")
                    .ScanEscapedUntil('\'')
                    .GetResult(&remaining, &match));
-  EXPECT_EQ("unset", remaining.ToString());
-  EXPECT_EQ("unset", match.ToString());
+  EXPECT_EQ("unset", remaining);
+  EXPECT_EQ("unset", match);
 }
 
 TEST_F(ScannerTest, ZeroOrOneLiteral) {
   StringPiece remaining, match;
   EXPECT_TRUE(
       Scanner("abc").ZeroOrOneLiteral("abC").GetResult(&remaining, &match));
-  EXPECT_EQ("abc", remaining.ToString());
-  EXPECT_EQ("", match.ToString());
+  EXPECT_EQ("abc", remaining);
+  EXPECT_EQ("", match);
 
   EXPECT_TRUE(
       Scanner("abcd").ZeroOrOneLiteral("ab").ZeroOrOneLiteral("c").GetResult(
           &remaining, &match));
-  EXPECT_EQ("d", remaining.ToString());
-  EXPECT_EQ("abc", match.ToString());
+  EXPECT_EQ("d", remaining);
+  EXPECT_EQ("abc", match);
 
   EXPECT_TRUE(
       Scanner("").ZeroOrOneLiteral("abc").GetResult(&remaining, &match));
-  EXPECT_EQ("", remaining.ToString());
-  EXPECT_EQ("", match.ToString());
+  EXPECT_EQ("", remaining);
+  EXPECT_EQ("", match);
 }
 
 // Test output of GetResult (including the forms with optional params),
@@ -215,24 +215,24 @@ TEST_F(ScannerTest, CaptureAndGetResult) {
                   .StopCapture()
                   .Any(Scanner::SPACE)
                   .GetResult(&remaining, &match));
-  EXPECT_EQ("second", remaining.ToString());
-  EXPECT_EQ("first", match.ToString());
+  EXPECT_EQ("second", remaining);
+  EXPECT_EQ("first", match);
   EXPECT_TRUE(scan.GetResult());
   remaining = "";
   EXPECT_TRUE(scan.GetResult(&remaining));
-  EXPECT_EQ("second", remaining.ToString());
+  EXPECT_EQ("second", remaining);
   remaining = "";
   match = "";
   EXPECT_TRUE(scan.GetResult(&remaining, &match));
-  EXPECT_EQ("second", remaining.ToString());
-  EXPECT_EQ("first", match.ToString());
+  EXPECT_EQ("second", remaining);
+  EXPECT_EQ("first", match);
 
   scan.RestartCapture().One(Scanner::LETTER).One(Scanner::LETTER);
   remaining = "";
   match = "";
   EXPECT_TRUE(scan.GetResult(&remaining, &match));
-  EXPECT_EQ("cond", remaining.ToString());
-  EXPECT_EQ("se", match.ToString());
+  EXPECT_EQ("cond", remaining);
+  EXPECT_EQ("se", match);
 }
 
 // Tests that if StopCapture is not called, then calling GetResult, then
@@ -242,14 +242,14 @@ TEST_F(ScannerTest, MultipleGetResultExtendsCapture) {
 
   Scanner scan("one2three");
   EXPECT_TRUE(scan.Many(Scanner::LETTER).GetResult(&remaining, &match));
-  EXPECT_EQ("2three", remaining.ToString());
-  EXPECT_EQ("one", match.ToString());
+  EXPECT_EQ("2three", remaining);
+  EXPECT_EQ("one", match);
   EXPECT_TRUE(scan.Many(Scanner::DIGIT).GetResult(&remaining, &match));
-  EXPECT_EQ("three", remaining.ToString());
-  EXPECT_EQ("one2", match.ToString());
+  EXPECT_EQ("three", remaining);
+  EXPECT_EQ("one2", match);
   EXPECT_TRUE(scan.Many(Scanner::LETTER).GetResult(&remaining, &match));
-  EXPECT_EQ("", remaining.ToString());
-  EXPECT_EQ("one2three", match.ToString());
+  EXPECT_EQ("", remaining);
+  EXPECT_EQ("one2three", match);
 }
 
 TEST_F(ScannerTest, FailedMatchDoesntChangeResult) {
@@ -258,8 +258,8 @@ TEST_F(ScannerTest, FailedMatchDoesntChangeResult) {
   StringPiece remaining = "rem";
   StringPiece match = "match";
   EXPECT_FALSE(scan.One(Scanner::SPACE).GetResult(&remaining, &match));
-  EXPECT_EQ("rem", remaining.ToString());
-  EXPECT_EQ("match", match.ToString());
+  EXPECT_EQ("rem", remaining);
+  EXPECT_EQ("match", match);
 }
 
 TEST_F(ScannerTest, DefaultCapturesAll) {
@@ -271,8 +271,8 @@ TEST_F(ScannerTest, DefaultCapturesAll) {
                   .AnySpace()
                   .Any(Scanner::LETTER)
                   .GetResult(&remaining, &match));
-  EXPECT_EQ("", remaining.ToString());
-  EXPECT_EQ("a b", match.ToString());
+  EXPECT_EQ("", remaining);
+  EXPECT_EQ("a b", match);
 }
 
 TEST_F(ScannerTest, AllCharClasses) {
diff --git a/tensorflow/core/lib/strings/str_util.cc b/tensorflow/core/lib/strings/str_util.cc
index 4598b8ccc7..cab8f81585 100644
--- a/tensorflow/core/lib/strings/str_util.cc
+++ b/tensorflow/core/lib/strings/str_util.cc
@@ -332,7 +332,7 @@ string StringReplace(StringPiece s, StringPiece oldsub, StringPiece newsub,
                      bool replace_all) {
   // TODO(jlebar): We could avoid having to shift data around in the string if
   // we had a StringPiece::find() overload that searched for a StringPiece.
-  string res = s.ToString();
+  string res = std::string(s);
   size_t pos = 0;
   while ((pos = res.find(oldsub.data(), pos, oldsub.size())) != string::npos) {
     res.replace(pos, oldsub.size(), newsub.data(), newsub.size());
@@ -449,7 +449,7 @@ bool SplitAndParseAsFloats(StringPiece text, char delim,
   return SplitAndParseAsInts<float>(text, delim,
                                     [](StringPiece str, float* value) {
                                       return strings::safe_strtof(
-                                          str.ToString().c_str(), value);
+                                          std::string(str).c_str(), value);
                                     },
                                     result);
 }
diff --git a/tensorflow/core/lib/strings/str_util.h b/tensorflow/core/lib/strings/str_util.h
index e97d00b975..c887db7eff 100644
--- a/tensorflow/core/lib/strings/str_util.h
+++ b/tensorflow/core/lib/strings/str_util.h
@@ -205,7 +205,7 @@ std::vector<string> Split(StringPiece text, StringPiece delims, Predicate p) {
       if ((i == text.size()) || (delims.find(text[i]) != StringPiece::npos)) {
         StringPiece token(text.data() + token_start, i - token_start);
         if (p(token)) {
-          result.push_back(token.ToString());
+          result.push_back(std::string(token));
         }
         token_start = i + 1;
       }
diff --git a/tensorflow/core/platform/env.cc b/tensorflow/core/platform/env.cc
index b9a9ef85eb..fe7d0aa7d1 100644
--- a/tensorflow/core/platform/env.cc
+++ b/tensorflow/core/platform/env.cc
@@ -92,7 +92,7 @@ Env::Env() : file_system_registry_(new FileSystemRegistryImpl) {}
 Status Env::GetFileSystemForFile(const string& fname, FileSystem** result) {
   StringPiece scheme, host, path;
   io::ParseURI(fname, &scheme, &host, &path);
-  FileSystem* file_system = file_system_registry_->Lookup(scheme.ToString());
+  FileSystem* file_system = file_system_registry_->Lookup(std::string(scheme));
   if (!file_system) {
     if (scheme.empty()) {
       scheme = "[local]";
@@ -166,7 +166,7 @@ bool Env::FilesExist(const std::vector<string>& files,
   for (const auto& file : files) {
     StringPiece scheme, host, path;
     io::ParseURI(file, &scheme, &host, &path);
-    files_per_fs[scheme.ToString()].push_back(file);
+    files_per_fs[std::string(scheme)].push_back(file);
   }
 
   std::unordered_map<string, Status> per_file_status;
diff --git a/tensorflow/core/platform/env_test.cc b/tensorflow/core/platform/env_test.cc
index a70a417e6a..c461a40086 100644
--- a/tensorflow/core/platform/env_test.cc
+++ b/tensorflow/core/platform/env_test.cc
@@ -357,7 +357,7 @@ TEST_F(DefaultEnvTest, LocalTempFilename) {
   CHECK_EQ(error::OUT_OF_RANGE,
            file_to_read->Read(0 /* offset */, 1024 /* n */, &content, scratch)
                .code());
-  EXPECT_EQ("Null", content.ToString());
+  EXPECT_EQ("Null", content);
 
   // Delete the temporary file.
   TF_CHECK_OK(env->DeleteFile(filename));
diff --git a/tensorflow/core/platform/file_system.cc b/tensorflow/core/platform/file_system.cc
index b55e94d552..922773684b 100644
--- a/tensorflow/core/platform/file_system.cc
+++ b/tensorflow/core/platform/file_system.cc
@@ -158,7 +158,7 @@ Status FileSystem::RecursivelyCreateDir(const string& dirname) {
   std::reverse(sub_dirs.begin(), sub_dirs.end());
 
   // Now create the directories.
-  string built_path = remaining_dir.ToString();
+  string built_path = std::string(remaining_dir);
   for (const StringPiece sub_dir : sub_dirs) {
     built_path = io::JoinPath(built_path, sub_dir);
     Status status = CreateDir(io::CreateURI(scheme, host, built_path));
diff --git a/tensorflow/core/platform/file_system_helper.cc b/tensorflow/core/platform/file_system_helper.cc
index 22c5057281..0ba0e6304f 100644
--- a/tensorflow/core/platform/file_system_helper.cc
+++ b/tensorflow/core/platform/file_system_helper.cc
@@ -59,7 +59,7 @@ Status GetMatchingPaths(FileSystem* fs, Env* env, const string& pattern,
   string fixed_prefix = pattern.substr(0, pattern.find_first_of("*?[\\"));
   string eval_pattern = pattern;
   std::vector<string> all_files;
-  string dir = io::Dirname(fixed_prefix).ToString();
+  string dir = std::string(io::Dirname(fixed_prefix));
   // If dir is empty then we need to fix up fixed_prefix and eval_pattern to
   // include . as the top level directory.
   if (dir.empty()) {
diff --git a/tensorflow/core/platform/file_system_test.cc b/tensorflow/core/platform/file_system_test.cc
index f261b8f576..c0a16c95f9 100644
--- a/tensorflow/core/platform/file_system_test.cc
+++ b/tensorflow/core/platform/file_system_test.cc
@@ -125,7 +125,7 @@ class InterPlanetaryFileSystem : public NullFileSystem {
     ASSERT_EQ(scheme, "ipfs");
     ASSERT_EQ(host, "solarsystem");
     str_util::ConsumePrefix(&path, "/");
-    *parsed_path = path.ToString();
+    *parsed_path = std::string(path);
   }
 
   std::map<string, std::set<string>> celestial_bodies_ = {
diff --git a/tensorflow/core/util/command_line_flags.cc b/tensorflow/core/util/command_line_flags.cc
index 480ce94fca..8c27d01917 100644
--- a/tensorflow/core/util/command_line_flags.cc
+++ b/tensorflow/core/util/command_line_flags.cc
@@ -32,7 +32,7 @@ bool ParseStringFlag(tensorflow::StringPiece arg, tensorflow::StringPiece flag,
   if (str_util::ConsumePrefix(&arg, "--") &&
       str_util::ConsumePrefix(&arg, flag) &&
       str_util::ConsumePrefix(&arg, "=")) {
-    *value_parsing_ok = hook(arg.ToString());
+    *value_parsing_ok = hook(std::string(arg));
     return true;
   }
 
diff --git a/tensorflow/core/util/env_var.cc b/tensorflow/core/util/env_var.cc
index c844850179..8d43bcc927 100644
--- a/tensorflow/core/util/env_var.cc
+++ b/tensorflow/core/util/env_var.cc
@@ -28,7 +28,7 @@ namespace tensorflow {
 Status ReadBoolFromEnvVar(StringPiece env_var_name, bool default_val,
                           bool* value) {
   *value = default_val;
-  const char* tf_env_var_val = getenv(env_var_name.ToString().c_str());
+  const char* tf_env_var_val = getenv(std::string(env_var_name).c_str());
   if (tf_env_var_val == nullptr) {
     return Status::OK();
   }
@@ -48,7 +48,7 @@ Status ReadBoolFromEnvVar(StringPiece env_var_name, bool default_val,
 Status ReadInt64FromEnvVar(StringPiece env_var_name, int64 default_val,
                            int64* value) {
   *value = default_val;
-  const char* tf_env_var_val = getenv(env_var_name.ToString().c_str());
+  const char* tf_env_var_val = getenv(std::string(env_var_name).c_str());
   if (tf_env_var_val == nullptr) {
     return Status::OK();
   }
@@ -62,11 +62,11 @@ Status ReadInt64FromEnvVar(StringPiece env_var_name, int64 default_val,
 
 Status ReadStringFromEnvVar(StringPiece env_var_name, StringPiece default_val,
                             string* value) {
-  const char* tf_env_var_val = getenv(env_var_name.ToString().c_str());
+  const char* tf_env_var_val = getenv(std::string(env_var_name).c_str());
   if (tf_env_var_val != nullptr) {
     *value = tf_env_var_val;
   } else {
-    *value = default_val.ToString();
+    *value = std::string(default_val);
   }
   return Status::OK();
 }
diff --git a/tensorflow/core/util/example_proto_fast_parsing.cc b/tensorflow/core/util/example_proto_fast_parsing.cc
index 7946fa1782..3ce7988057 100644
--- a/tensorflow/core/util/example_proto_fast_parsing.cc
+++ b/tensorflow/core/util/example_proto_fast_parsing.cc
@@ -353,7 +353,7 @@ bool TestFastParse(const string& serialized, Example* example) {
     // I.e. last entry in the map overwrites all the previous ones.
     parsed::FeatureMapEntry& name_and_feature =
         parsed_example[parsed_example_size - i - 1];
-    string name = name_and_feature.first.ToString();
+    string name = std::string(name_and_feature.first);
     if ((*features.mutable_feature()).count(name) > 0) continue;
 
     auto& value = (*features.mutable_feature())[name];