boost::format with variadic template arguments

Question

Suppose I have a printf-like function (used for logging) utilizing perfect forwarding:

template
void awesome_printf         


        

Answer 1

As is usual with variadic templates, you can use recursion:

std::string awesome_printf_helper(boost::format& f){
    return boost::str(f);
}

template
std::string awesome_printf_helper(boost::format& f, T&& t, Args&&... args){
    return awesome_printf_helper(f % std::forward(t), std::forward(args)...);
}

template
void awesome_printf(std::string const& fmt, Arguments&&... args)
{
    boost::format f(fmt);

    auto result = awesome_printf_helper(f, std::forward(args)...);

    // call BlackBoxLogFunction with result as appropriate, e.g.
    std::cout << result;
}

Demo.

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In C++17, simply (f % ... % std::forward(args)); will do.