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Diffstat (limited to 'security/sandbox/chromium/base/bind_helpers.h')
-rw-r--r-- | security/sandbox/chromium/base/bind_helpers.h | 69 |
1 files changed, 69 insertions, 0 deletions
diff --git a/security/sandbox/chromium/base/bind_helpers.h b/security/sandbox/chromium/base/bind_helpers.h new file mode 100644 index 0000000000..37065a07ab --- /dev/null +++ b/security/sandbox/chromium/base/bind_helpers.h @@ -0,0 +1,69 @@ +// Copyright (c) 2011 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 BASE_BIND_HELPERS_H_ +#define BASE_BIND_HELPERS_H_ + +#include <stddef.h> + +#include <type_traits> +#include <utility> + +#include "base/bind.h" +#include "base/callback.h" +#include "base/memory/weak_ptr.h" +#include "build/build_config.h" + +// This defines a set of simple functions and utilities that people want when +// using {Once,Repeating}Callback<> and Bind{Once,Repeating}(). + +namespace base { + +// Creates a null callback. +class BASE_EXPORT NullCallback { + public: + template <typename R, typename... Args> + operator RepeatingCallback<R(Args...)>() const { + return RepeatingCallback<R(Args...)>(); + } + template <typename R, typename... Args> + operator OnceCallback<R(Args...)>() const { + return OnceCallback<R(Args...)>(); + } +}; + +// Creates a callback that does nothing when called. +class BASE_EXPORT DoNothing { + public: + template <typename... Args> + operator RepeatingCallback<void(Args...)>() const { + return Repeatedly<Args...>(); + } + template <typename... Args> + operator OnceCallback<void(Args...)>() const { + return Once<Args...>(); + } + // Explicit way of specifying a specific callback type when the compiler can't + // deduce it. + template <typename... Args> + static RepeatingCallback<void(Args...)> Repeatedly() { + return BindRepeating([](Args... args) {}); + } + template <typename... Args> + static OnceCallback<void(Args...)> Once() { + return BindOnce([](Args... args) {}); + } +}; + +// Useful for creating a Closure that will delete a pointer when invoked. Only +// use this when necessary. In most cases MessageLoop::DeleteSoon() is a better +// fit. +template <typename T> +void DeletePointer(T* obj) { + delete obj; +} + +} // namespace base + +#endif // BASE_BIND_HELPERS_H_ |