num_list2.qbk

来自「Boost provides free peer-reviewed portab」· QBK 代码 · 共 31 行

[/==============================================================================
    Copyright (C) 2001-2008 Joel de Guzman
    Copyright (C) 2001-2008 Hartmut Kaiser

    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 Number List - stuffing numbers into a std::vector]

This sample demontrates a parser for a comma separated list of numbers. The
numbers are inserted in a vector using phoenix.

[import ../../example/qi/num_list2.cpp]

[tutorial_numlist2]

The full cpp file for this example can be found here: [@../../example/qi/num_list2.cpp]

This, again, is the same parser as before. This time, instead of summing up the
numbers, we stuff them in a `std::vector`. `push_back` is supplied by
__phoenix__. The expression:

    push_back(ref(v), _1)

appends the parsed number. Like before, `_1` is a __phoenix__ placeholder for
the parsed result attribute. Also, like before, `ref(v)` tells __phoenix__ that
`v`, the `std::vector`, is a mutable reference.

[endsect]