nested_exception.h

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/*  Copyright (c) SILVERCODERS Ltd, http://silvercoders.com                                                                                  */
/*  Project homepage: https://github.com/docwire/docwire                                                                                     */
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#ifndef DOCWIRE_NESTED_EXCEPTION_H
#define DOCWIRE_NESTED_EXCEPTION_H
 
#include <exception>
 
namespace docwire::errors
{
 
template<typename T>
class nested : virtual public std::nested_exception, public T
{
public:
 
    nested(T&& t)
        : T(std::forward<T>(t))
    {
    }
 
    nested(const T& t)
        : T(t)
    {
    }
};
 
template <typename Inner, typename Outer>
auto make_nested(Inner&& inner, Outer&& outer)
{
    try
    {
        if constexpr (std::is_same_v<std::remove_cvref_t<Inner>, std::exception_ptr>)
            std::rethrow_exception(std::forward<Inner>(inner));
        else
            throw std::forward<Inner>(inner);
    }
    catch(...)
    {
        return nested<std::remove_cvref_t<Outer>>(std::forward<Outer>(outer));
    }
}
 
template <typename Inner, typename Outer, typename... Rest>
auto make_nested(Inner&& inner, Outer&& outer, Rest&&... rest)
{
    return make_nested(make_nested(std::forward<Inner>(inner), std::forward<Outer>(outer)), std::forward<Rest>(rest)...);
}
 
template <typename Inner, typename Outer, typename... Rest>
std::exception_ptr make_nested_ptr(Inner&& inner, Outer&& outer, Rest&&... rest)
{
    return std::make_exception_ptr(make_nested(std::forward<Inner>(inner), std::forward<Outer>(outer), std::forward<Rest>(rest)...));
}
 
} // namespace docwire::errors
 
#endif