73ef4ff3
 Hu Chunming
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[/
Copyright 2006-2007 John Maddock.
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:unicode Unicode and Boost.Regex]
There are two ways to use Boost.Regex with Unicode strings:
[h4 Rely on wchar_t]
If your platform's `wchar_t` type can hold Unicode strings, and your
platform's C/C++ runtime correctly handles wide character constants
(when passed to `std::iswspace` `std::iswlower` etc), then you can use
`boost::wregex` to process Unicode. However, there are several
disadvantages to this approach:
* It's not portable: there's no guarantee on the width of `wchar_t`, or
even whether the runtime treats wide characters as Unicode at all,
most Windows compilers do so, but many Unix systems do not.
* There's no support for Unicode-specific character classes: `[[:Nd:]]`, `[[:Po:]]` etc.
* You can only search strings that are encoded as sequences of wide
characters, it is not possible to search UTF-8, or even UTF-16 on many platforms.
[h4 Use a Unicode Aware Regular Expression Type.]
If you have the
[@http://www.ibm.com/software/globalization/icu/ ICU library], then
Boost.Regex provides a distinct regular expression type (boost::u32regex),
that supports both Unicode specific character properties, and the searching
of text that is encoded in either UTF-8, UTF-16, or UTF-32. See:
[link boost_regex.ref.non_std_strings.icu
ICU string class support].
[endsect]
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