TypedElementQueryContext.h

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// Copyright Epic Games, Inc. All Rights Reserved.
 
#pragma once
 
#include <type_traits>
#include "Elements/Framework/TypedElementQueryCapabilities.h"
#include "Elements/Framework/TypedElementQueryCapabilityForwarder.h"
 
namespace UE::Editor::DataStorage::Queries
{
    struct IContextContract;
 
    template<typename T>
    concept ContextCapability = std::is_base_of_v<IContextCapability, T> && !std::is_same_v<IContextCapability, T>;
 
    template<ContextCapability... Capabilities>
    struct TCapabilityStore : Capabilities... 
    {
        static constexpr bool bIsSingle = (EnumHasAnyFlags(Capabilities::Flags, EContextCapabilityFlags::SupportsSingle) && ...);
        static constexpr bool bIsBatch = (EnumHasAnyFlags(Capabilities::Flags, EContextCapabilityFlags::SupportsBatch) && ...);
    };
 
    template<ContextCapability... CapabilityTypes>
    struct TQueryContext final : Private::TForwarder<CapabilityTypes...>
    {
        using Capabilities = TCapabilityStore<CapabilityTypes...>;
 
        static_assert(Capabilities::bIsSingle || Capabilities::bIsBatch,
            "One or more capabilities that only support single or batch processing were mixed.");
 
        TQueryContext() = default;
        TQueryContext(IContextContract& Contract);
    };
    
    //
    // Implementations.
    //
    
    template<ContextCapability... CapabilityTypes>
    TQueryContext<CapabilityTypes...>::TQueryContext(IContextContract& Contract)
        : Private::TForwarder<CapabilityTypes...>(Contract)
    {
    }
} // namespace UE::Editor::DataStorage::Queries