Update ICU testing and usage.

test/quick_icu.cpp

@@ -0,0 +1,55 @@
+
+// Copyright 1998-2002 John Maddock
+// Copyright 2017 Peter Dimov
+//
+// 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
+
+// See library home page at http://www.boost.org/libs/regex
+
+#include <boost/regex/icu.hpp>
+#include <cassert>
+#include <string>
+
+bool validate_card_format(const std::string& s)
+{
+    static const boost::u32regex e = boost::make_u32regex("(\\d{4}[- ]){3}\\d{4}");
+    return boost::u32regex_match(s, e);
+}
+
+const boost::u32regex card_rx = boost::make_u32regex("\\A(\\d{3,4})[- ]?(\\d{4})[- ]?(\\d{4})[- ]?(\\d{4})\\z");
+const std::string machine_format("\\1\\2\\3\\4");
+const std::string human_format("\\1-\\2-\\3-\\4");
+
+std::string machine_readable_card_number(const std::string& s)
+{
+    return boost::u32regex_replace(s, card_rx, machine_format, boost::match_default | boost::format_sed);
+}
+
+std::string human_readable_card_number(const std::string& s)
+{
+    return boost::u32regex_replace(s, card_rx, human_format, boost::match_default | boost::format_sed);
+}
+
+int main()
+{
+    std::string s[ 4 ] = { "0000111122223333", "0000 1111 2222 3333", "0000-1111-2222-3333", "000-1111-2222-3333" };
+
+    assert( !validate_card_format( s[0] ) );
+    assert( machine_readable_card_number( s[0] ) == s[0] );
+    assert( human_readable_card_number( s[0] ) == s[2] );
+
+    assert( validate_card_format( s[1] ) );
+    assert( machine_readable_card_number( s[1] ) == s[0] );
+    assert( human_readable_card_number( s[1] ) == s[2] );
+
+    assert( validate_card_format( s[2] ) );
+    assert( machine_readable_card_number( s[2] ) == s[0] );
+    assert( human_readable_card_number( s[2] ) == s[2] );
+
+    assert( !validate_card_format( s[3] ) );
+
+    return 0;
+}