Helper macro to delegate function calls to member functions from attributes

delegate.cpp

// Distributed under the Boost Software License, Version 1.0.
// See accompanying file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt
// (c) 2015 Luc Hermitte
#include <vector>
#include <iostream>
#include <algorithm>
#include <list>
#define DELEGATE_TO(fname, attribute)                          \
    auto fname() const noexcept(noexcept(attribute.fname())) { \
        return attribute.fname();                              \
    }
// Will lead to cryptic message errors
#define DELEGATE_TO2(fname, attribute)                                               \
    template <typename... Args>                                                      \
    auto fname(Args &&... args) const noexcept(noexcept(attribute.fname(args...))) { \
        return attribute.fname(args...);                                             \
    }

template <typename T>
class sorted_vector final
{
public:
    sorted_vector() = default;
    sorted_vector(std::initializer_list<T> init)
        : m_vector(init)
        {
            std::sort(m_vector.begin(),m_vector.end());
        }

    DELEGATE_TO(cbegin, m_vector);
    DELEGATE_TO(cend  , m_vector);
    DELEGATE_TO(begin , m_vector);
    DELEGATE_TO(end   , m_vector);
    DELEGATE_TO(size  , m_vector);
    DELEGATE_TO(back  , m_vector);
    // DELEGATE_TO(empty , m_vector);
    DELEGATE_TO2(empty , m_vector);
    DELEGATE_TO2(operator[], m_vector);
    DELEGATE_TO2(swap, m_vector);

    // using m_vector::swap; won't work :(

private:
    std::vector<T> m_vector;
};

int main ()
{
    sorted_vector<int> s = {1, 2, 3};
    std::cout << std::boolalpha;
    std::cout << s.back() << "\n";
    std::cout << s.empty() << "\n";
    std::cout << s[0] << "\n";
    // std::cout << s["toto"];
}
// Vim: let $CXXFLAGS='-std=c++14'