Change scoped_ptr to a type alias for std::unique_ptr on OS_WIN

printing/backend/printing_info_win.h

 // Copyright (c) 2012 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 PRINTING_BACKEND_PRINTING_INFO_WIN_H_
 #define PRINTING_BACKEND_PRINTING_INFO_WIN_H_
 
 #include <objidl.h>
 #include <stdint.h>
 #include <winspool.h>
 
 #include "base/memory/scoped_ptr.h"
 #include "printing/printing_export.h"
 
 namespace printing {
 
 namespace internal {
 
 PRINTING_EXPORT uint8_t* GetDriverInfo(HANDLE printer, int level);
 PRINTING_EXPORT uint8_t* GetPrinterInfo(HANDLE printer, int level);
 
 // This class is designed to work with PRINTER_INFO_X structures
 // and calls GetPrinter internally with correctly allocated buffer.
 template <typename PrinterInfoType, int level>
 class PrinterInfo {
  public:
   bool Init(HANDLE printer) {
     buffer_.reset(GetPrinterInfo(printer, level));
-    return buffer_;
+    return buffer_ != nullptr;

[Vitaly Buka (NO REVIEWS), 2016/03/04 18:25:17]

is any warning without this?
I thought Chromium prefer checking pointers without comparing with null.

[dcheng, 2016/03/04 18:28:59]

It depends on the reviewer =P

With C++11 and explicit operator bool, this can no longer implicitly convert,
since it's not a place where a "context conversion to bool" is allowed (an
example of somewhere where it is allowed is if (x) { ... }).

So we have several choices:
- return static_cast<bool>(buffer_);
- return !!buffer_;  (my personal preferred option)
- return buffer_ != nullptr;  (some reviewers expressed that this might be
clearer)

[Vitaly Buka (NO REVIEWS), 2016/03/04 18:34:39]

Thanks. I like !! too, but current one is lgtm too.

[joedow, 2016/03/04 20:46:19]

I like !! as well to boolify but I have seen feedback both ways.

   }
 
   const PrinterInfoType* get() const {
     return reinterpret_cast<const PrinterInfoType*>(buffer_.get());
   }
 
  private:
   scoped_ptr<uint8_t[]> buffer_;
 };
 
 // This class is designed to work with DRIVER_INFO_X structures
 // and calls GetDriverInfo internally with correctly allocated buffer.
 template <typename DriverInfoType, int level>
 class DriverInfo {
  public:
   bool Init(HANDLE printer) {
     buffer_.reset(GetDriverInfo(printer, level));
-    return buffer_;
+    return buffer_ != nullptr;
   }
 
   const DriverInfoType* get() const {
     return reinterpret_cast<const DriverInfoType*>(buffer_.get());
   }
 
  private:
   scoped_ptr<uint8_t[]> buffer_;
 };
 
 }  // namespace internal
 
 typedef internal::PrinterInfo<PRINTER_INFO_2, 2> PrinterInfo2;
 typedef internal::PrinterInfo<PRINTER_INFO_5, 5> PrinterInfo5;
 
 typedef internal::DriverInfo<DRIVER_INFO_6, 6> DriverInfo6;
 
 }  // namespace printing
 
 #endif  // PRINTING_BACKEND_PRINTING_INFO_WIN_H_