#### Arguments

Arguments are also functions? You bet!

Until now, we have been dealing with expressions returning a nullary function. Arguments, on the other hand, evaluate to an N-ary function. An argument represents the Nth argument. There are a few predefined arguments arg1, arg2, arg3, arg4 and so on (and it's BLL counterparts: _1, _2, _3, _4 and so on). Examples:

    arg1 // one-or-more argument function that returns its first argument
    arg2 // two-or-more argument function that returns its second argument
    arg3 // three-or-more argument function that returns its third argument

`argN` returns the Nth argument. Examples:

    int i = 3;
    char const* s = "Hello World";
    std::cout << arg1(i) << std::endl;        // prints 3
    std::cout << arg2(i, s) << std::endl;     // prints "Hello World"

(See arguments.cpp)