You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
79 lines
2.2 KiB
79 lines
2.2 KiB
// Copyright 2017 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_CONTAINERS_UNIQUE_PTR_ADAPTERS_H_
|
|
#define BASE_CONTAINERS_UNIQUE_PTR_ADAPTERS_H_
|
|
|
|
#include <memory>
|
|
|
|
namespace base {
|
|
|
|
// This transparent comparator allows to lookup by raw pointer in
|
|
// a container of unique pointers. This functionality is based on C++14
|
|
// extensions to std::set/std::map interface, and can also be used
|
|
// with base::flat_set/base::flat_map.
|
|
//
|
|
// Example usage:
|
|
// Foo* foo = ...
|
|
// std::set<std::unique_ptr<Foo>, base::UniquePtrComparator> set;
|
|
// set.insert(std::unique_ptr<Foo>(foo));
|
|
// ...
|
|
// auto it = set.find(foo);
|
|
// EXPECT_EQ(foo, it->get());
|
|
//
|
|
// You can find more information about transparent comparisons here:
|
|
// http://en.cppreference.com/w/cpp/utility/functional/less_void
|
|
struct UniquePtrComparator {
|
|
using is_transparent = int;
|
|
|
|
template <typename T>
|
|
bool operator()(const std::unique_ptr<T>& lhs,
|
|
const std::unique_ptr<T>& rhs) const {
|
|
return lhs < rhs;
|
|
}
|
|
|
|
template <typename T>
|
|
bool operator()(const T* lhs, const std::unique_ptr<T>& rhs) const {
|
|
return lhs < rhs.get();
|
|
}
|
|
|
|
template <typename T>
|
|
bool operator()(const std::unique_ptr<T>& lhs, const T* rhs) const {
|
|
return lhs.get() < rhs;
|
|
}
|
|
};
|
|
|
|
// UniquePtrMatcher is useful for finding an element in a container of
|
|
// unique_ptrs when you have the raw pointer.
|
|
//
|
|
// Example usage:
|
|
// std::vector<std::unique_ptr<Foo>> vector;
|
|
// Foo* element = ...
|
|
// auto iter = std::find_if(vector.begin(), vector.end(),
|
|
// MatchesUniquePtr(element));
|
|
//
|
|
// Example of erasing from container:
|
|
// EraseIf(v, MatchesUniquePtr(element));
|
|
//
|
|
template <class T, class Deleter = std::default_delete<T>>
|
|
struct UniquePtrMatcher {
|
|
explicit UniquePtrMatcher(T* t) : t_(t) {}
|
|
|
|
bool operator()(const std::unique_ptr<T, Deleter>& o) {
|
|
return o.get() == t_;
|
|
}
|
|
|
|
private:
|
|
T* const t_;
|
|
};
|
|
|
|
template <class T, class Deleter = std::default_delete<T>>
|
|
UniquePtrMatcher<T, Deleter> MatchesUniquePtr(T* t) {
|
|
return UniquePtrMatcher<T, Deleter>(t);
|
|
}
|
|
|
|
} // namespace base
|
|
|
|
#endif // BASE_CONTAINERS_UNIQUE_PTR_ADAPTERS_H_
|