Bluetooth UUIDs should be case-insensitive.

device/bluetooth/bluetooth_uuid.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef DEVICE_BLUETOOTH_BLUETOOTH_UUID_H_
 #define DEVICE_BLUETOOTH_BLUETOOTH_UUID_H_
 
 #include <string>
 
 namespace device {
 
 // Opaque wrapper around a Bluetooth UUID. Instances of UUID represent the
 // 128-bit universally unique identifiers (UUIDs) of profiles and attributes
 // used in Bluetooth based communication, such as a peripheral's services,
 // characteristics, and characteristic descriptors. An instance are
 // constructed using a string representing 16, 32, or 128 bit UUID formats.
 class BluetoothUUID {
  public:
   // Possible representation formats used during construction.
   enum Format {
     kFormatInvalid,
     kFormat16Bit,
     kFormat32Bit,
     kFormat128Bit
   };
 
   // Single argument constructor. |uuid| can be a 16, 32, or 128 bit UUID
   // represented as a 4, 8, or 36 character string with the following
   // formats:
-  //   XXXX
-  //   0xXXXX
-  //   XXXXXXXX
-  //   0xXXXXXXXX
-  //   XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX
+  //   xxxx
+  //   0xxxxx
+  //   xxxxxxxx
+  //   0xxxxxxxxx
+  //   xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx
   //
   // 16 and 32 bit UUIDs will be internally converted to a 128 bit UUID using
   // the base UUID defined in the Bluetooth specification, hence custom UUIDs
   // should be provided in the 128-bit format. If |uuid| is in an unsupported
   // format, the result might be invalid. Use IsValid to check for validity
   // after construction.
   explicit BluetoothUUID(const std::string& uuid);
 
   // Default constructor does nothing. Since BluetoothUUID is copyable, this
   // constructor is useful for initializing member variables and assigning a
   // value to them later. The default constructor will initialize an invalid
   // UUID by definition and the string accessors will return an empty string.
   BluetoothUUID();
   virtual ~BluetoothUUID();
 
   // Returns true, if the UUID is in a valid canonical format.
   bool IsValid() const;
 
   // Returns the representation format of the UUID. This reflects the format
   // that was provided during construction.
   Format format() const { return format_; }
 
   // Returns the value of the UUID as a string. The representation format is
   // based on what was passed in during construction. For the supported sizes,
   // this representation can have the following formats:
-  //   - 16 bit:  XXXX
-  //   - 32 bit:  XXXXXXXX
-  //   - 128 bit: XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX
-  // where X is a lowercase hex digit.
+  //   - 16 bit:  xxxx
+  //   - 32 bit:  xxxxxxxx
+  //   - 128 bit: xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx
+  // where x is a lowercase hex digit.
   const std::string& value() const { return value_; }
 
   // Returns the underlying 128-bit value as a string in the following format:
-  //   XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX
-  // where X is a lowercase hex digit.
+  //   xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx
+  // where x is a lowercase hex digit.
   const std::string& canonical_value() const { return canonical_value_; }
 
   // Permit sufficient comparison to allow a UUID to be used as a key in a
   // std::map.
   bool operator<(const BluetoothUUID& uuid) const;
 
   // Equality operators.
   bool operator==(const BluetoothUUID& uuid) const;
   bool operator!=(const BluetoothUUID& uuid) const;
 
  private:
   // String representation of the UUID that was used during construction. For
   // the supported sizes, this representation can have the following formats:
-  //   - 16 bit:  XXXX
-  //   - 32 bit:  XXXXXXXX
-  //   - 128 bit: XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX
+  //   - 16 bit:  xxxx
+  //   - 32 bit:  xxxxxxxx
+  //   - 128 bit: xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx
   Format format_;
   std::string value_;
 
   // The 128-bit string representation of the UUID.
   std::string canonical_value_;
 };
 
 // This is required by gtest to print a readable output on test failures.
 void PrintTo(const BluetoothUUID& uuid, std::ostream* out);
 
 }  // namespace device
 
 #endif  // DEVICE_BLUETOOTH_BLUETOOTH_UUID_H_