From: Sean Hunt (rideau3_at_[hidden])
Date: 2008-03-16 22:30:48
Robert Dailey wrote:
> On Sun, Mar 16, 2008 at 5:44 PM, Eric Niebler <eric_at_[hidden]>
>> I've made a small addition ... the formatter can be a lambda, too, if
>> you #include <boost/xpressive/regex_actions.hpp>. The above can now be
>> written simply as:
>> using xpressive::ref;
>> string output = regex_replace(input, rx, ref(replacements)[_]);
>> Here, "_" gets substituted with a sub_match representing the current
>> match. You can also use s1, s2, etc., to access the other sub-matches.
> How is "[_]" legal C++ syntax?
> Unsubscribe & other changes: http://lists.boost.org/mailman/listinfo.cgi/boost
"_" is just an identifier, so "[_]" is calling the  operator with the
parameter being whatever "_" refers to. In this case, it allows for the
creation of lambda expressions.
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