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mirror of https://github.com/SerenityOS/serenity synced 2024-07-09 15:30:47 +00:00
serenity/AK/Traits.h
Karol Kosek e575ee4462 AK+Kernel: Unify Traits<T>::equals()'s argument order on different types
There was a small mishmash of argument order, as seen on the table:

                 | Traits<T>::equals(U, T) | Traits<T>::equals(T, U)
   ============= | ======================= | =======================
   uses equals() | HashMap                 | Vector, HashTable
defines equals() | *String[^1]             | ByteBuffer

[^1]: String, DeprecatedString, their Fly-type equivalents and KString.

This mostly meant that you couldn't use a StringView for finding a value
in Vector<String>.

I'm changing the order of arguments to make the trait type itself first
(`Traits<T>::equals(T, U)`), as I think it's more expected and makes us
more consistent with the rest of the functions that put the stored type
first (like StringUtils functions and binary_serach). I've also renamed
the variable name "other" in find functions to "entry" to give more
importance to the value.

With this change, each of the following lines will now compile
successfully:

    Vector<String>().contains_slow("WHF!"sv);
    HashTable<String>().contains("WHF!"sv);
    HashMap<ByteBuffer, int>().contains("WHF!"sv.bytes());
2023-08-23 20:21:09 +02:00

86 lines
2.6 KiB
C++

/*
* Copyright (c) 2018-2022, Andreas Kling <kling@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#pragma once
#include <AK/BitCast.h>
#include <AK/Concepts.h>
#include <AK/Forward.h>
#include <AK/HashFunctions.h>
#include <AK/StringHash.h>
namespace AK {
template<typename T>
struct GenericTraits {
using PeekType = T&;
using ConstPeekType = T const&;
static constexpr bool is_trivial() { return false; }
static constexpr bool is_trivially_serializable() { return false; }
static constexpr bool equals(T const& a, T const& b) { return a == b; }
template<Concepts::HashCompatible<T> U>
static bool equals(T const& self, U const& other) { return self == other; }
};
template<typename T>
struct Traits : public GenericTraits<T> {
};
template<Integral T>
struct Traits<T> : public GenericTraits<T> {
static constexpr bool is_trivial() { return true; }
static constexpr bool is_trivially_serializable() { return true; }
static constexpr unsigned hash(T value)
{
if constexpr (sizeof(T) < 8)
return int_hash(value);
else
return u64_hash(value);
}
};
#ifndef KERNEL
template<FloatingPoint T>
struct Traits<T> : public GenericTraits<T> {
static constexpr bool is_trivial() { return true; }
static constexpr bool is_trivially_serializable() { return true; }
static constexpr unsigned hash(T value)
{
if constexpr (sizeof(T) < 8)
return int_hash(bit_cast<u32>(value));
else
return u64_hash(bit_cast<u64>(value));
}
};
#endif
template<typename T>
requires(IsPointer<T> && !Detail::IsPointerOfType<char, T>) struct Traits<T> : public GenericTraits<T> {
static unsigned hash(T p) { return ptr_hash(p); }
static constexpr bool is_trivial() { return true; }
};
template<Enum T>
struct Traits<T> : public GenericTraits<T> {
static unsigned hash(T value) { return Traits<UnderlyingType<T>>::hash(to_underlying(value)); }
static constexpr bool is_trivial() { return Traits<UnderlyingType<T>>::is_trivial(); }
static constexpr bool is_trivially_serializable() { return Traits<UnderlyingType<T>>::is_trivially_serializable(); }
};
template<typename T>
requires(Detail::IsPointerOfType<char, T>) struct Traits<T> : public GenericTraits<T> {
static unsigned hash(T const value) { return string_hash(value, strlen(value)); }
static constexpr bool equals(T const a, T const b) { return strcmp(a, b); }
static constexpr bool is_trivial() { return true; }
};
}
#if USING_AK_GLOBALLY
using AK::GenericTraits;
using AK::Traits;
#endif