I want to catch an exception and bundle it within my own exception and throw upwards

Question

I have a class that manages resources. It takes a Loader class that can retrieve the resource from a path. Loader is an abstract base class, so anyone could make a new loade

Answer 1

How about a nested exception?

try { /* ... */ }
catch (...)
{
    throw MyException("An error occurred", std::current_exception());
}

Just make a suitable class that stores the exception:

struct MyException : std::exception
{
    std::string message;
    std::exception_ptr nested_exception;

    MyException(std::string m, std::exception_ptr e)
    : message(std::move(m))
    , nested_exception(std::move(e))
    { }

    // ...
};

When the exception is caught, the catcher can rethrow the nested exception:

try { /* load resource */ }
catch (MyException & e)
{
    log("Resource loading failed: " + e.what());
    std::rethrow_exception(e.nested_exception);
}

In fact, this entire logic is already provided by the standard library via std::throw_with_nested.