Re-committing http://codereview.chromium.org/8736001/ originally committed revision=112305

third_party/libphonenumber/cpp/src/default_logger.h

-// Copyright (C) 2011 Google Inc.
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-// http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-// Author: Philippe Liard
-
-#ifndef I18N_PHONENUMBERS_DEFAULT_LOGGER_H_
-#define I18N_PHONENUMBERS_DEFAULT_LOGGER_H_
-
-#include <stdio.h>
-
-#include <string>
-
-#include "logger.h"
-
-using std::string;
-
-// Make the logging functions private (not declared in logger.h) as the client
-// should not have any reason to use them.
-namespace {
-
-using i18n::phonenumbers::Logger;
-
-// Class template used to inline the right implementation for the T -> string
-// conversion.
-template <typename T>
-struct ConvertToString;
-
-template <typename T>
-struct ConvertToString {
-  static inline string DoWork(const T& s) {
-    return string(s);
-  }
-};
-
-template <>
-struct ConvertToString<int> {
-  static inline string DoWork(const int& n) {
-    char buffer[16];
-#if defined(OS_WIN)
-    _itoa_s(n, buffer, sizeof(buffer), 10);
-#else
-    snprintf(buffer, sizeof(buffer), "%d", n);
-#endif
-    return string(buffer);
-  }
-};
-
-class LoggerHandler {
- public:
-  LoggerHandler(Logger* impl) : impl_(impl) {}
-
-  ~LoggerHandler() {
-    if (impl_) {
-      impl_->WriteMessage("\n");
-    }
-  }
-
-  template <typename T>
-  LoggerHandler& operator<<(const T& value) {
-    if (impl_) {
-      impl_->WriteMessage(ConvertToString<T>::DoWork(value));
-    }
-    return *this;
-  }
-
- private:
-  Logger* const impl_;
-};
-
-}  // namespace
-
-namespace i18n {
-namespace phonenumbers {
-
-// Default logger implementation used by PhoneNumberUtil class. It outputs the
-// messages to the standard output.
-class StdoutLogger : public Logger {
- public:
-  virtual ~StdoutLogger() {}
-
-  virtual void WriteLevel();
-  virtual void WriteMessage(const string& msg);
-};
-
-}  // namespace phonenumbers
-}  // namespace i18n
-
-#endif  // I18N_PHONENUMBERS_DEFAULT_LOGGER_H_