ladybird/AK/Concepts.h
Ali Mohammad Pur f879e04133 AK: Add a concept for iterable containers
This concept describes a type with a begin()/end() pair that can
function as an iterator, given the following criteria:
- The return type of begin() is comparable with the return type of
  end(), and the comparison (with operator!=) yields a bool
- The object returned from begin() can be pre-incremented
- The iterator has an operator*() implementation
2021-07-22 22:56:20 +02:00

82 lines
1.6 KiB
C++

/*
* Copyright (c) 2020, the SerenityOS developers.
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#pragma once
#include <AK/IterationDecision.h>
#include <AK/StdLibExtras.h>
namespace AK::Concepts {
template<typename T>
concept Integral = IsIntegral<T>;
template<typename T>
concept FloatingPoint = IsFloatingPoint<T>;
template<typename T>
concept Arithmetic = IsArithmetic<T>;
template<typename T>
concept Signed = IsSigned<T>;
template<typename T>
concept Unsigned = IsUnsigned<T>;
template<typename T>
concept Enum = IsEnum<T>;
template<typename T, typename U>
concept SameAs = IsSame<T, U>;
// FIXME: remove once Clang formats these properly.
// clang-format off
template<typename Func, typename... Args>
concept VoidFunction = requires(Func func, Args... args)
{
{
func(args...)
}
-> SameAs<void>;
};
template<typename Func, typename... Args>
concept IteratorFunction = requires(Func func, Args... args)
{
{
func(args...)
}
-> SameAs<IterationDecision>;
};
template<typename T, typename EndT>
concept IteratorPairWith = requires(T it, EndT end)
{
*it;
{ it != end } -> SameAs<bool>;
++it;
};
template<typename T>
concept IterableContainer = requires
{
{ declval<T>().begin() } -> IteratorPairWith<decltype(declval<T>().end())>;
};
// clang-format on
}
using AK::Concepts::Arithmetic;
using AK::Concepts::Enum;
using AK::Concepts::FloatingPoint;
using AK::Concepts::Integral;
using AK::Concepts::IterableContainer;
using AK::Concepts::IteratorFunction;
using AK::Concepts::IteratorPairWith;
using AK::Concepts::Signed;
using AK::Concepts::Unsigned;
using AK::Concepts::VoidFunction;