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// Copyright 2019 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.
#include <hstring.h>
#include "base/base_export.h"
namespace base {
namespace win {
// HStringReference is an HSTRING representation of a null terminated
// string backed by memory that outlives the HStringReference instance.
// If you need an HSTRING class that manages its own memory, you should
// use ScopedHString instead.
// Note that HStringReference requires certain functions that are only
// available on Windows 8 and later, and that these functions need to be
// delayloaded to avoid breaking Chrome on Windows 7.
// Callers MUST check the return value of ResolveCoreWinRTStringDelayLoad()
// *before* using HStringReference.
// One-time Initialization for HStringReference:
// const bool success = HStringReference::ResolveCoreWinRTStringDelayload();
// if (success) {
// // HStringReference can be used.
// } else {
// // Handle error.
// }
// Example use:
// HStringReference string(L"abc");
class BASE_EXPORT HStringReference {
// Loads all required HSTRING functions, available from Win8 and onwards.
static bool ResolveCoreWinRTStringDelayload();
HStringReference(const wchar_t* str, size_t len);
explicit HStringReference(const wchar_t* str);
HSTRING Get() const { return hstring_; }
// HSTRING_HEADER is a structure that contains a pointer to the string
// passed into the constructor, along with its length.
// Since HSTRING is a pointer to HSTRING_HEADER, HStringReference
// cannot be copyable, moveable or assignable, as that would invalidate
// the HSTRING we're passing out to clients.
// In the future, we can consider implementing these methods by storing
// the string passed in the constructor and re-creating the HSTRING and
// HSTRING_HEADER datastructures. For now, we'll keep things simple and
// forbid these operations.
HStringReference(const HStringReference&) = delete;
HStringReference& operator=(const HStringReference&) = delete;
HSTRING hstring_ = nullptr;
HSTRING_HEADER hstring_header_;
} // namespace win
} // namespace base