diff --git a/base/base_tests/file_name_utils_tests.cpp b/base/base_tests/file_name_utils_tests.cpp
index e49f575c4e..c12c3fce34 100644
--- a/base/base_tests/file_name_utils_tests.cpp
+++ b/base/base_tests/file_name_utils_tests.cpp
@@ -76,6 +76,9 @@ UNIT_TEST(FilePath_Slash)
 
 UNIT_TEST(FilePath_Join)
 {
+  TEST_EQUAL("dir", base::JoinPath("", "dir"), ());
+  TEST_EQUAL("dir", base::JoinPath("", "/dir"), ());
+  TEST_EQUAL("dir/file", base::JoinPath("", "dir", "file"), ());
   TEST_EQUAL("omim/strings.txt", base::JoinPath("omim", "strings.txt"), ());
   TEST_EQUAL("omim/strings.txt", base::JoinPath("omim/", "strings.txt"), ());
   TEST_EQUAL("../../omim/strings.txt", base::JoinPath("..", "..", "omim", "strings.txt"), ());
diff --git a/base/base_tests/string_utils_test.cpp b/base/base_tests/string_utils_test.cpp
index e897f4d910..a00c39750f 100644
--- a/base/base_tests/string_utils_test.cpp
+++ b/base/base_tests/string_utils_test.cpp
@@ -882,6 +882,8 @@ UNIT_TEST(StartsWith)
   std::string s("xyz");
   TEST(StartsWith(s, ""), ());
   TEST(StartsWith(s, "x"), ());
+  TEST(StartsWith(s, 'x'), ());
+  TEST(!StartsWith(s, 'z'), ());
   TEST(StartsWith(s, "xyz"), ());
   TEST(!StartsWith(s, "xyzabc"), ());
   TEST(!StartsWith(s, "ayz"), ());
@@ -906,6 +908,8 @@ UNIT_TEST(EndsWith)
     std::string const s("xyz");
     TEST(EndsWith(s, ""), ());
     TEST(EndsWith(s, "z"), ());
+    TEST(EndsWith(s, 'z'), ());
+    TEST(!EndsWith(s, 'x'), ());
     TEST(EndsWith(s, "yz"), ());
     TEST(EndsWith(s, "xyz"), ());
     TEST(!EndsWith(s, "abcxyz"), ());
diff --git a/base/file_name_utils.cpp b/base/file_name_utils.cpp
index a514b2f701..ba1cba5e20 100644
--- a/base/file_name_utils.cpp
+++ b/base/file_name_utils.cpp
@@ -49,31 +49,31 @@ string GetNameFromFullPathWithoutExt(string const & path)
 
 string GetDirectory(string const & name)
 {
-  string const sep = GetNativeSeparator();
-  size_t const sepSize = sep.size();
+  auto const sep = GetNativeSeparator();
+  size_t const sepSize = sizeof(sep);
 
   string::size_type i = name.rfind(sep);
   if (i == string::npos)
     return ".";
-  while (i > sepSize && (name.substr(i - sepSize, sepSize) == sep))
+  while (i > sepSize && (name[i - sepSize] == sep))
     i -= sepSize;
-  return i == 0 ? sep : name.substr(0, i);
+  return name.substr(0, i ? i : sepSize);
 }
 
-string GetNativeSeparator()
+string::value_type GetNativeSeparator()
 {
 #ifdef OMIM_OS_WINDOWS
-    return "\\";
+    return '\\';
 #else
-    return "/";
+    return '/';
 #endif
 }
 
 string AddSlashIfNeeded(string const & path)
 {
-  string const sep = GetNativeSeparator();
+  auto const sep = GetNativeSeparator();
   string::size_type const pos = path.rfind(sep);
-  if ((pos != string::npos) && (pos + sep.size() == path.size()))
+  if ((pos != string::npos) && (pos + sizeof(sep) == path.size()))
     return path;
   return path + sep;
 }
diff --git a/base/file_name_utils.hpp b/base/file_name_utils.hpp
index 287abbc773..193b4e8f6e 100644
--- a/base/file_name_utils.hpp
+++ b/base/file_name_utils.hpp
@@ -25,8 +25,8 @@ std::string GetNameFromFullPathWithoutExt(std::string const & path);
 /// root directory. If the argument is a single component, returns ".".
 std::string GetDirectory(std::string const & path);
 
-/// Get folder separator for specific platform
-std::string GetNativeSeparator();
+/// Get native folder separator for the platform.
+std::string::value_type GetNativeSeparator();
 
 /// Add the terminating slash to the folder path std::string if it's not already there.
 std::string AddSlashIfNeeded(std::string const & path);
diff --git a/base/string_utils.cpp b/base/string_utils.cpp
index 9468e26da9..af8a97817b 100644
--- a/base/string_utils.cpp
+++ b/base/string_utils.cpp
@@ -313,6 +313,11 @@ bool StartsWith(std::string const & s1, char const * s2)
   return (s1.compare(0, strlen(s2), s2) == 0);
 }
 
+bool StartsWith(std::string const & s, std::string::value_type c)
+{
+  return s.empty() ? false : s.front() == c;
+}
+
 bool StartsWith(std::string const & s1, std::string const & s2)
 {
   return (s1.compare(0, s2.length(), s2) == 0);
@@ -335,6 +340,11 @@ bool EndsWith(std::string const & s1, char const * s2)
   return (s1.compare(n - m, m, s2) == 0);
 }
 
+bool EndsWith(std::string const & s, std::string::value_type c)
+{
+  return s.empty() ? false : s.back() == c;
+}
+
 bool EndsWith(std::string const & s1, std::string const & s2)
 {
   return s1.size() >= s2.size() && s1.compare(s1.size() - s2.size(), s2.size(), s2) == 0;
diff --git a/base/string_utils.hpp b/base/string_utils.hpp
index 76545a3664..328c61c416 100644
--- a/base/string_utils.hpp
+++ b/base/string_utils.hpp
@@ -143,14 +143,14 @@ public:
   using reference = std::string;
   using iterator_category = std::input_iterator_tag;
 
-  // *NOTE* |s| must be not temporary!
+  // *NOTE* |s| must not be a temporary!
   TokenizeIterator(std::string const & s, DelimFn const & delimFn)
     : m_start(s.begin()), m_end(s.begin()), m_finish(s.end()), m_delimFn(delimFn)
   {
     Move();
   }
 
-  // *NOTE* |s| must be not temporary!
+  // *NOTE* |s| must not be a temporary!
   TokenizeIterator(UniString const & s, DelimFn const & delimFn)
     : m_start(s.begin()), m_end(s.begin()), m_finish(s.end()), m_delimFn(delimFn)
   {
@@ -591,15 +591,13 @@ bool StartsWith(IterT1 beg, IterT1 end, IterT2 begPrefix, IterT2 endPrefix)
 }
 
 bool StartsWith(UniString const & s, UniString const & p);
-
 bool StartsWith(std::string const & s1, char const * s2);
-
+bool StartsWith(std::string const & s, std::string::value_type c);
 bool StartsWith(std::string const & s1, std::string const & s2);
 
 bool EndsWith(UniString const & s1, UniString const & s2);
-
 bool EndsWith(std::string const & s1, char const * s2);
-
+bool EndsWith(std::string const & s, std::string::value_type c);
 bool EndsWith(std::string const & s1, std::string const & s2);
 
 // If |s| starts with |prefix|, deletes it from |s| and returns true.
diff --git a/platform/localization.cpp b/platform/localization.cpp
index f166b0af85..4b547f19ae 100644
--- a/platform/localization.cpp
+++ b/platform/localization.cpp
@@ -27,6 +27,7 @@ LocalizedUnits GetLocalizedUnits(measurement_utils::Units units, MeasurementType
     case measurement_utils::Units::Imperial: return {GetLocalizedString("foot"), GetLocalizedString("mile")};
     case measurement_utils::Units::Metric: return {GetLocalizedString("meter"), GetLocalizedString("kilometer")};
     }
+    break;
   case MeasurementType::Speed:
     switch (units)
     {
diff --git a/platform/platform.cpp b/platform/platform.cpp
index 6fc706a942..0523b75c68 100644
--- a/platform/platform.cpp
+++ b/platform/platform.cpp
@@ -125,6 +125,16 @@ void Platform::SetSettingsDir(string const & path)
   m_settingsDir = base::AddSlashIfNeeded(path);
 }
 
+std::string Platform::SettingsPathForFile(std::string const & file) const
+{
+  return base::JoinPath(SettingsDir(), file);
+}
+
+std::string Platform::WritablePathForFile(std::string const & file) const
+{
+  return base::JoinPath(WritableDir(), file);
+}
+
 string Platform::ReadPathForFile(string const & file, string searchScope) const
 {
   if (searchScope.empty())
@@ -297,9 +307,9 @@ bool Platform::MkDirChecked(string const & dirName)
 // static
 bool Platform::MkDirRecursively(string const & dirName)
 {
-  auto const sep = base::GetNativeSeparator();
+  string::value_type const sep[] = { base::GetNativeSeparator(), 0};
   string path = strings::StartsWith(dirName, sep) ? sep : "";
-  auto const tokens = strings::Tokenize(dirName, sep.c_str());
+  auto const tokens = strings::Tokenize(dirName, sep);
   for (auto const & t : tokens)
   {
     path = base::JoinPath(path, t);
diff --git a/platform/platform.hpp b/platform/platform.hpp
index 53c6e2338b..c26699fbba 100644
--- a/platform/platform.hpp
+++ b/platform/platform.hpp
@@ -134,7 +134,7 @@ public:
   /// Set writable dir — use for testing and linux stuff only
   void SetWritableDirForTests(std::string const & path);
   /// @return full path to file in user's writable directory
-  std::string WritablePathForFile(std::string const & file) const { return WritableDir() + file; }
+  std::string WritablePathForFile(std::string const & file) const;
   /// Uses m_writeableDir [w], m_resourcesDir [r], m_settingsDir [s].
   std::string ReadPathForFile(std::string const & file,
                               std::string searchScope = std::string()) const;
@@ -185,7 +185,7 @@ public:
   std::string const & SettingsDir() const { return m_settingsDir; }
   void SetSettingsDir(std::string const & path);
   /// @return full path to file in the settings directory
-  std::string SettingsPathForFile(std::string const & file) const { return SettingsDir() + file; }
+  std::string SettingsPathForFile(std::string const & file) const;
 
   /// @return reader for file decriptor.
   /// @throws FileAbsentException
diff --git a/platform/platform_tests/apk_test.cpp b/platform/platform_tests/apk_test.cpp
index 50990919d0..08a9e14a25 100644
--- a/platform/platform_tests/apk_test.cpp
+++ b/platform/platform_tests/apk_test.cpp
@@ -14,112 +14,113 @@
 #include <numeric>
 #include <string>
 
-using namespace std;
-
-namespace
+namespace apk_test
 {
-  char const * arrFiles[] = {
-    "copyright.html",
-    "resources-mdpi_clear/symbols.sdf",
-    "resources-mdpi_clear/symbols.png",
-    "resources-hdpi_clear/symbols.sdf",
-    "resources-hdpi_clear/symbols.png",
-    "resources-xhdpi_clear/symbols.sdf",
-    "resources-xhdpi_clear/symbols.png",
-    "categories.txt",
-    "categories_cuisines.txt",
-    "classificator.txt",
-    "types.txt",
-    "fonts_blacklist.txt",
-    "fonts_whitelist.txt",
-    "languages.txt",
-    "unicode_blocks.txt",
-    "drules_proto_clear.bin",
-    "external_resources.txt",
-    "packed_polygons.bin",
-    "countries.txt"
-  };
+using std::string, std::vector;
 
-  class ApkTester : public threads::IRoutine
+char const * arrFiles[] = {
+  "copyright.html",
+  "resources-mdpi_clear/symbols.sdf",
+  "resources-mdpi_clear/symbols.png",
+  "resources-hdpi_clear/symbols.sdf",
+  "resources-hdpi_clear/symbols.png",
+  "resources-xhdpi_clear/symbols.sdf",
+  "resources-xhdpi_clear/symbols.png",
+  "categories.txt",
+  "categories_cuisines.txt",
+  "classificator.txt",
+  "types.txt",
+  "fonts_blacklist.txt",
+  "fonts_whitelist.txt",
+  "languages.txt",
+  "unicode_blocks.txt",
+  "drules_proto_clear.bin",
+  "external_resources.txt",
+  "packed_polygons.bin",
+  "countries.txt"
+};
+
+class ApkTester : public threads::IRoutine
+{
+  static const int COUNT = ARRAY_SIZE(arrFiles);
+  string const & m_cont;
+
+public:
+  explicit ApkTester(string const & cont) : m_cont(cont), m_hashes(COUNT)
   {
-    static const int COUNT = ARRAY_SIZE(arrFiles);
-    string const & m_cont;
+  }
 
-  public:
-    explicit ApkTester(string const & cont) : m_cont(cont), m_hashes(COUNT)
+  virtual void Do()
+  {
+    string const prefix("assets/");
+
+    while (true)
     {
-    }
-
-    virtual void Do()
-    {
-      string const prefix("assets/");
-
-      while (true)
+      size_t ind = rand() % COUNT;
+      if (m_hashes[ind] != 0)
       {
-        size_t ind = rand() % COUNT;
-        if (m_hashes[ind] != 0)
-        {
-          ind = COUNT;
-          for (size_t i = 0; i < COUNT; ++i)
-            if (m_hashes[i] == 0)
-            {
-              ind = i;
-              break;
-            }
-        }
+        ind = COUNT;
+        for (size_t i = 0; i < COUNT; ++i)
+          if (m_hashes[i] == 0)
+          {
+            ind = i;
+            break;
+          }
+      }
 
-        if (ind == COUNT)
-          break;
+      if (ind == COUNT)
+        break;
 
-        try
-        {
-          ZipFileReader reader(m_cont, prefix + arrFiles[ind]);
+      try
+      {
+        ZipFileReader reader(m_cont, prefix + arrFiles[ind]);
 
-          size_t const size = reader.Size();
-          vector<char> buffer(size);
-          reader.Read(0, &buffer[0], size);
+        size_t const size = reader.Size();
+        vector<char> buffer(size);
+        reader.Read(0, &buffer[0], size);
 
-          m_hashes[ind] = accumulate(buffer.begin(), buffer.end(), static_cast<uint64_t>(0));
-        }
-        catch (Reader::Exception const & ex)
-        {
-          LOG(LERROR, (ex.Msg()));
-          break;
-        }
+        m_hashes[ind] = accumulate(buffer.begin(), buffer.end(), static_cast<uint64_t>(0));
+      }
+      catch (Reader::Exception const & ex)
+      {
+        LOG(LERROR, (ex.Msg()));
+        break;
       }
     }
+  }
 
-    vector<uint64_t> m_hashes;
-  };
-}
+  vector<uint64_t> m_hashes;
+};
 
+/*
 UNIT_TEST(ApkReader_Multithreaded)
 {
-  /// @todo Update test with current apk path.
+/// @todo Update test with current apk path.
   string const path = GetPlatform().WritableDir() + "../android/MapsWithMePro/bin/MapsWithMePro-production.apk";
 
-  uint64_t size;
-  if (!base::GetFileSize(path, size))
-  {
-    LOG(LINFO, ("Apk not found"));
-    return;
-  }
-
-  srand(static_cast<unsigned>(size));
-
-  size_t const count = 20;
-  base::thread_pool::routine_simple::ThreadPool pool(count);
-
-  for (size_t i = 0; i < count; ++i)
-    pool.Add(make_unique<ApkTester>(path));
-
-  pool.Join();
-
-  typedef ApkTester const * PtrT;
-  PtrT etalon = dynamic_cast<PtrT>(pool.GetRoutine(0));
-  for (size_t i = 1; i < count; ++i)
-  {
-    PtrT p = dynamic_cast<PtrT>(pool.GetRoutine(i));
-    TEST_EQUAL(etalon->m_hashes, p->m_hashes, ());
-  }
+uint64_t size;
+if (!base::GetFileSize(path, size))
+{
+  LOG(LINFO, ("Apk not found"));
+  return;
 }
+
+srand(static_cast<unsigned>(size));
+
+size_t const count = 20;
+base::thread_pool::routine_simple::ThreadPool pool(count);
+
+for (size_t i = 0; i < count; ++i)
+  pool.Add(make_unique<ApkTester>(path));
+
+pool.Join();
+
+typedef ApkTester const * PtrT;
+PtrT etalon = dynamic_cast<PtrT>(pool.GetRoutine(0));
+for (size_t i = 1; i < count; ++i)
+{
+  PtrT p = dynamic_cast<PtrT>(pool.GetRoutine(i));
+  TEST_EQUAL(etalon->m_hashes, p->m_hashes, ());
+}
+*/
+}  // namespace apk_test
diff --git a/platform/platform_tests/platform_test.cpp b/platform/platform_tests/platform_test.cpp
index b2516e2480..52afdbc5c1 100644
--- a/platform/platform_tests/platform_test.cpp
+++ b/platform/platform_tests/platform_test.cpp
@@ -181,26 +181,29 @@ UNIT_TEST(GetFileSize)
   TEST(!pl.GetFileSizeByName("adsmngfuwrbfyfwe", size), ());
   TEST(!pl.IsFileExistsByFullPath("adsmngfuwrbfyfwe"), ());
 
+  char const kContent[] = "HOHOHO";
+  size_t const kSize = ARRAY_SIZE(kContent);
   std::string const fileName = pl.WritablePathForFile(TEST_FILE_NAME);
   {
     FileWriter testFile(fileName);
-    testFile.Write("HOHOHO", 6);
+    testFile.Write(kContent, kSize);
   }
   size = 0;
   TEST(Platform::GetFileSizeByFullPath(fileName, size), ());
-  TEST_EQUAL(size, 6, ());
+  TEST_EQUAL(size, kSize, ());
 
   FileWriter::DeleteFileX(fileName);
+  TEST(!pl.IsFileExistsByFullPath(fileName), ());
 
   {
-    FileWriter testFile(pl.WritablePathForFile(TEST_FILE_NAME));
-    testFile.Write("HOHOHO", 6);
+    FileWriter testFile(fileName);
+    testFile.Write(kContent, kSize);
   }
   size = 0;
   TEST(pl.GetFileSizeByName(TEST_FILE_NAME, size), ());
-  TEST_EQUAL(size, 6, ());
+  TEST_EQUAL(size, kSize, ());
 
-  FileWriter::DeleteFileX(pl.WritablePathForFile(TEST_FILE_NAME));
+  FileWriter::DeleteFileX(fileName);
 }
 
 UNIT_TEST(CpuCores)
diff --git a/platform/platform_win.cpp b/platform/platform_win.cpp
index a0954ae196..1b9989f3b5 100644
--- a/platform/platform_win.cpp
+++ b/platform/platform_win.cpp
@@ -1,5 +1,6 @@
 #include "platform/platform.hpp"
 
+#include "base/file_name_utils.hpp"
 #include "base/scope_guard.hpp"
 #include "base/logging.hpp"
 
@@ -70,9 +71,10 @@ Platform::Platform()
   // writable path:
   // 1. the same as resources if we have write access to this folder
   // 2. otherwise, use system-specific folder
+  string const tmpFilePath = base::JoinPath(m_resourcesDir, "mapswithmetmptestfile");
   try
   {
-    FileWriter tmpfile(m_resourcesDir + "mapswithmetmptestfile");
+    FileWriter tmpfile(tmpFilePath);
     tmpfile.Write("Hi from Alex!", 13);
     m_writableDir = m_resourcesDir;
   }
@@ -80,17 +82,17 @@ Platform::Platform()
   {
     CHECK(GetUserWritableDir(m_writableDir), ("Can't get writable directory"));
   }
-  FileWriter::DeleteFileX(m_resourcesDir + "mapswithmetmptestfile");
+  FileWriter::DeleteFileX(tmpFilePath);
 
   m_settingsDir = m_writableDir;
   char pathBuf[MAX_PATH] = {0};
   GetTempPathA(MAX_PATH, pathBuf);
   m_tmpDir = pathBuf;
 
-  LOG(LDEBUG, ("Resources Directory:", m_resourcesDir));
-  LOG(LDEBUG, ("Writable Directory:", m_writableDir));
-  LOG(LDEBUG, ("Tmp Directory:", m_tmpDir));
-  LOG(LDEBUG, ("Settings Directory:", m_settingsDir));
+  LOG(LINFO, ("Resources Directory:", m_resourcesDir));
+  LOG(LINFO, ("Writable Directory:", m_writableDir));
+  LOG(LINFO, ("Tmp Directory:", m_tmpDir));
+  LOG(LINFO, ("Settings Directory:", m_settingsDir));
 }
 
 bool Platform::IsFileExistsByFullPath(string const & filePath)
diff --git a/search/search_tests/house_detector_tests.cpp b/search/search_tests/house_detector_tests.cpp
index 309d086ccf..fa99955586 100644
--- a/search/search_tests/house_detector_tests.cpp
+++ b/search/search_tests/house_detector_tests.cpp
@@ -24,6 +24,8 @@
 #include <string>
 #include <vector>
 
+namespace house_detector_tests
+{
 using namespace std;
 using platform::LocalCountryFile;
 
@@ -496,3 +498,4 @@ UNIT_TEST(HS_MWMSearch)
   LOG(LINFO, ("Matched =", matched, "Not matched =", notMatched, "Not found =", all - matched - notMatched));
   LOG(LINFO, ("All count =", all, "Percent matched =", matched / double(all)));
 }
+}  // namespace house_detector_tests