43 lines
1.6 KiB
Plaintext
43 lines
1.6 KiB
Plaintext
[/
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Copyright 2006-2007 John Maddock.
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Distributed under the Boost Software License, Version 1.0.
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(See accompanying file LICENSE_1_0.txt or copy at
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http://www.boost.org/LICENSE_1_0.txt).
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]
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[section:unicode Unicode and Boost.Regex]
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There are two ways to use Boost.Regex with Unicode strings:
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[h4 Rely on wchar_t]
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If your platform's `wchar_t` type can hold Unicode strings, and your
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platform's C/C++ runtime correctly handles wide character constants
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(when passed to `std::iswspace` `std::iswlower` etc), then you can use
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`boost::wregex` to process Unicode. However, there are several
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disadvantages to this approach:
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* It's not portable: there's no guarantee on the width of `wchar_t`, or
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even whether the runtime treats wide characters as Unicode at all,
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most Windows compilers do so, but many Unix systems do not.
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* There's no support for Unicode-specific character classes: `[[:Nd:]]`, `[[:Po:]]` etc.
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* You can only search strings that are encoded as sequences of wide
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characters, it is not possible to search UTF-8, or even UTF-16 on many platforms.
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[h4 Use a Unicode Aware Regular Expression Type.]
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If you have the
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[@http://www.ibm.com/software/globalization/icu/ ICU library], then
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Boost.Regex can be
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[link boost_regex.install.building_with_unicode_and_icu_su
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configured to make use
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of it], and provide a distinct regular expression type (boost::u32regex),
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that supports both Unicode specific character properties, and the searching
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of text that is encoded in either UTF-8, UTF-16, or UTF-32. See:
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[link boost_regex.ref.non_std_strings.icu
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ICU string class support].
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[endsect]
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