| [/============================================================================== |
| Copyright (C) 2001-2010 Joel de Guzman |
| Copyright (C) 2001-2005 Dan Marsden |
| Copyright (C) 2001-2010 Thomas Heller |
| |
| 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) |
| ===============================================================================/] |
| |
| [section 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 [@../../example/arguments.cpp arguments.cpp]) |
| |
| [blurb __tip__ Learn more about arguments [link phoenix.modules.core.arguments here.]] |
| |
| [endsect] |
