Add strings::AsciiToLower fast function.

2 files changed, 19 insertions, 0 deletions

diff --git a/base/string_utils.cpp b/base/string_utils.cpp
index edc2e57d6a..41862ae82a 100644
--- a/base/string_utils.cpp
+++ b/base/string_utils.cpp
@@ -104,6 +104,22 @@ UniString Normalize(UniString const & s)
   return result;
 }
 
+namespace
+{
+  char ascii_to_lower(char in)
+  {
+    static char const diff = 'Z'-'z';
+    if (in <= 'Z' && in >= 'A')
+      return (in-diff);
+    return in;
+  }
+}
+
+void AsciiToLower(string & s)
+{
+  transform(s.begin(), s.end(), s.begin(), &ascii_to_lower);
+}
+
 bool EqualNoCase(string const & s1, string const & s2)
 {
   return MakeLowerCase(s1) == MakeLowerCase(s2);
diff --git a/base/string_utils.hpp b/base/string_utils.hpp
index c58228110a..7268b8b0c6 100644
--- a/base/string_utils.hpp
+++ b/base/string_utils.hpp
@@ -28,8 +28,11 @@ public:
 UniString MakeLowerCase(UniString const & s);
 void MakeLowerCase(UniString & s);
 UniString Normalize(UniString const & s);
+/// For implementation @see base/normilize_unicode.cpp
 void Normalize(UniString & s);
 
+void AsciiToLower(string & s);
+
 void MakeLowerCase(string & s);
 string MakeLowerCase(string const & s);
 bool EqualNoCase(string const & s1, string const & s2);