mirror of
https://github.com/LadybirdBrowser/ladybird.git
synced 2024-11-22 15:40:19 +00:00
ae3ffdd521
This patch adds the `USING_AK_GLOBALLY` macro which is enabled by default, but can be overridden by build flags. This is a step towards integrating Jakt and AK types.
72 lines
1.5 KiB
C++
72 lines
1.5 KiB
C++
/*
|
|
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
|
|
*
|
|
* SPDX-License-Identifier: BSD-2-Clause
|
|
*/
|
|
|
|
#pragma once
|
|
|
|
#include <AK/StdLibExtras.h>
|
|
#include <AK/Types.h>
|
|
|
|
namespace AK {
|
|
|
|
struct DefaultComparator {
|
|
template<typename T, typename S>
|
|
[[nodiscard]] constexpr int operator()(T& lhs, S& rhs)
|
|
{
|
|
if (lhs > rhs)
|
|
return 1;
|
|
|
|
if (lhs < rhs)
|
|
return -1;
|
|
|
|
return 0;
|
|
}
|
|
};
|
|
|
|
template<typename Container, typename Needle, typename Comparator = DefaultComparator>
|
|
constexpr auto binary_search(
|
|
Container&& haystack,
|
|
Needle&& needle,
|
|
size_t* nearby_index = nullptr,
|
|
Comparator comparator = Comparator {}) -> decltype(&haystack[0])
|
|
{
|
|
if (haystack.size() == 0) {
|
|
if (nearby_index)
|
|
*nearby_index = 0;
|
|
return nullptr;
|
|
}
|
|
|
|
size_t low = 0;
|
|
size_t high = haystack.size() - 1;
|
|
while (low <= high) {
|
|
size_t middle = low + (high - low) / 2;
|
|
|
|
int comparison = comparator(needle, haystack[middle]);
|
|
|
|
if (comparison < 0)
|
|
if (middle != 0)
|
|
high = middle - 1;
|
|
else
|
|
break;
|
|
else if (comparison > 0)
|
|
low = middle + 1;
|
|
else {
|
|
if (nearby_index)
|
|
*nearby_index = middle;
|
|
return &haystack[middle];
|
|
}
|
|
}
|
|
|
|
if (nearby_index)
|
|
*nearby_index = min(low, high);
|
|
|
|
return nullptr;
|
|
}
|
|
|
|
}
|
|
|
|
#if USING_AK_GLOBALLY
|
|
using AK::binary_search;
|
|
#endif
|