/usr/include/boost/wave/cpplexer/ is in libboost1.46-dev 1.46.1-7ubuntu3.
This file is owned by root:root, with mode 0o755.
..
/usr/include/boost/wave/cpplexer/convert_trigraphs.hpp
/usr/include/boost/wave/cpplexer/cpp_lex_interface.hpp
/usr/include/boost/wave/cpplexer/cpp_lex_interface_generator.hpp
/usr/include/boost/wave/cpplexer/cpp_lex_iterator.hpp
/usr/include/boost/wave/cpplexer/cpp_lex_token.hpp
/usr/include/boost/wave/cpplexer/cpplexer_exceptions.hpp
/usr/include/boost/wave/cpplexer/detect_include_guards.hpp
/usr/include/boost/wave/cpplexer/re2clex/
/usr/include/boost/wave/cpplexer/re2clex/aq.hpp
/usr/include/boost/wave/cpplexer/re2clex/cpp_re.hpp
/usr/include/boost/wave/cpplexer/re2clex/cpp_re2c_lexer.hpp
/usr/include/boost/wave/cpplexer/re2clex/scanner.hpp
/usr/include/boost/wave/cpplexer/token_cache.hpp
/usr/include/boost/wave/cpplexer/validate_universal_char.hpp