NoneOf.h

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// Copyright Epic Games, Inc. All Rights Reserved.
 
#pragma once
 
#include "CoreTypes.h"
#include "Algo/Common.h"
#include "Templates/Invoke.h"
 
 
namespace Algo
{
    /**
     * Checks if no element in the range is truthy.
     *
     * @param  Range  The range to check.
     *
     * @return  true if no element is truthy, false otherwise.
     */
    template <typename RangeType>
    FORCEINLINE bool NoneOf(const RangeType& Range)
    {
        for (const auto& Element : Range)
        {
            if (Element)
            {
                return false;
            }
        }
 
        return true;
    }
 
    /**
     * Checks if no projection of the elements in the range is truthy.
     *
     * @param  Range       The range to check.
     * @param  Projection  The projection to apply to each element.
     *
     * @return  true if none of the projections are truthy, false otherwise.
     */
    template <typename RangeType, typename ProjectionType>
    FORCEINLINE bool NoneOf(const RangeType& Range, ProjectionType Projection)
    {
        for (const auto& Element : Range)
        {
            if (Invoke(Projection, Element))
            {
                return false;
            }
        }
 
        return true;
    }
 
    /**
     * Checks if no projection of the elements in the range is truthy.
     * Should be used when the range iterator doesn't return a reference.
     *
     * @param  Range       The range to check.
     * @param  Projection  The projection to apply to each element.
     *
     * @return  true if none of the projections are truthy, false otherwise.
     */
    template <typename RangeType, typename ProjectionType>
    FORCEINLINE bool NoneOf(const RangeType& Range, ProjectionType Projection, ENoRef NoRef)
    {
        for (const auto Element : Range)
        {
            if (Invoke(Projection, Element))
            {
                return false;
            }
        }
 
        return true;
    }
}