libs/regex/doc/unicode.qbk
[/ 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 can be [link boost_regex.install.building_with_unicode_and_icu_su configured to make use of it], and provide 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]