type_wrapper.h

/*****************************************************************************
 * VCLib                                                                     *
 * Visual Computing Library                                                  *
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 * Copyright(C) 2021-2025                                                    *
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 * ISTI - Italian National Research Council                                  *
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 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the              *
 * Mozilla Public License Version 2.0                                        *
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 ****************************************************************************/
 
#ifndef VCL_BASE_TYPE_WRAPPER_H
#define VCL_BASE_TYPE_WRAPPER_H
 
#include "variadic_templates.h"
 
namespace vcl {
 
template<typename... Args>
struct TypeWrapper
{
    static constexpr uint size() { return sizeof...(Args); }
};
 
// note: specialization from variadic_templates.h
template<typename... Args>
struct FirstType<TypeWrapper<Args...>>
{
    using type = std::tuple_element<0, std::tuple<Args...>>::type;
};
 
// note: specialization from variadic_templates.h
template<typename... Args>
uint indexInTypePack(std::type_index ti, TypeWrapper<Args...>)
{
    return indexInTypePack<Args...>(ti);
}
 
// note: specialization from variadic_templates.h
template<typename T, typename... Us>
struct IndexInTypes<T, TypeWrapper<Us...>>
{
    static constexpr uint value = indexInTypePack<T, Us...>();
};
 
// note: specialization from variadic_templates.h
template<uint I, typename... T>
struct TypeAt<I, TypeWrapper<T...>>
{
    using type = TypeAt<I, T...>::type;
};
 
// note: specialization from variadic_templates.h
template<typename... Args>
struct NumberOfTypes<TypeWrapper<Args...>> : public NumberOfTypes<Args...>
{
};
 
// note: specialization from variadic_templates.h
template<typename... T>
struct ForEachType<TypeWrapper<T...>> : public ForEachType<T...>
{
};
 
} // namespace vcl
 
#endif // VCL_BASE_TYPE_WRAPPER_H