Please see the relevant part from my build log below. gcc.compile.c++ ../../../../../bin/lib/re_0_02_0/impl/test/header-reno_config~pimpl~h.test/gcc-3.4.4/debug/link-static/header-reno_config~pimpl~h.o In file included from /cygdrive/c/code/lib/boost-trunk/boost/regex/v4/regex_traits.hpp:35, from /cygdrive/c/code/lib/boost-trunk/boost/regex/regex_traits.hpp:27, from /cygdrive/c/code/lib/boost-trunk/boost/regex/v4/regex.hpp:39, from /cygdrive/c/code/lib/boost-trunk/boost/regex.hpp:31, from /cygdrive/c/code/lib/re_0_02_0/re/reno_config.pimpl.h:10, from header-test.cpp:4: /cygdrive/c/code/lib/boost-trunk/boost/regex/v4/regex_traits_defaults.hpp: In function `ptrdiff_t boost::re_detail::global_length(const charT*) [with charT = wchar_t]': /cygdrive/c/code/lib/boost-trunk/boost/regex/v4/regex_traits_defaults.hpp:234: error: `wcslen' is not a member of `std' In file included from /cygdrive/c/code/lib/boost-trunk/boost/regex/v4/regex_traits.hpp:44, from /cygdrive/c/code/lib/boost-trunk/boost/regex/regex_traits.hpp:27, from /cygdrive/c/code/lib/boost-trunk/boost/regex/v4/regex.hpp:39, from /cygdrive/c/code/lib/boost-trunk/boost/regex.hpp:31, from /cygdrive/c/code/lib/re_0_02_0/re/reno_config.pimpl.h:10, from header-test.cpp:4: /cygdrive/c/code/lib/boost-trunk/boost/regex/v4/c_regex_traits.hpp: At global scope: /cygdrive/c/code/lib/boost-trunk/boost/regex/v4/c_regex_traits.hpp:104: error: ISO C++ forbids declaration of `wstring' with no type /cygdrive/c/code/lib/boost-trunk/boost/regex/v4/c_regex_traits.hpp:104: error: expected `;' before "string_type" /cygdrive/c/code/lib/boost-trunk/boost/regex/v4/c_regex_traits.hpp:122: error: `string_type' does not name a type /cygdrive/c/code/lib/boost-trunk/boost/regex/v4/c_regex_traits.hpp:123: error: `string_type' does not name a type /cygdrive/c/code/lib/boost-trunk/boost/regex/v4/c_regex_traits.hpp:126: error: `string_type' does not name a type /cygdrive/c/code/lib/boost-trunk/boost/regex/v4/c_regex_traits.hpp: In static member function `static size_t boost::c_regex_traits<wchar_t>::length(const wchar_t*)': /cygdrive/c/code/lib/boost-trunk/boost/regex/v4/c_regex_traits.hpp:110: error: `wcslen' is not a member of `std' /cygdrive/c/code/lib/boost-trunk/boost/regex/v4/c_regex_traits.hpp: In member function `wchar_t boost::c_regex_traits<wchar_t>::translate_nocase(wchar_t) const': /cygdrive/c/code/lib/boost-trunk/boost/regex/v4/c_regex_traits.hpp:119: error: `towlower' is not a member of `std' In file included from /cygdrive/c/code/lib/boost-trunk/boost/regex/v4/regex.hpp:76, from /cygdrive/c/code/lib/boost-trunk/boost/regex.hpp:31, from /cygdrive/c/code/lib/re_0_02_0/re/reno_config.pimpl.h:10, from header-test.cpp:4: /cygdrive/c/code/lib/boost-trunk/boost/regex/v4/sub_match.hpp: At global scope: /cygdrive/c/code/lib/boost-trunk/boost/regex/v4/sub_match.hpp:186: error: `std::wstring' has not been declared /cygdrive/c/code/lib/boost-trunk/boost/regex/v4/sub_match.hpp:186: error: `const_iterator' was not declared in this scope /cygdrive/c/code/lib/boost-trunk/boost/regex/v4/sub_match.hpp:186: error: template argument 1 is invalid /cygdrive/c/code/lib/boost-trunk/boost/regex/v4/sub_match.hpp:186: error: ISO C++ forbids declaration of `wssub_match' with no type In file included from /cygdrive/c/code/lib/boost-trunk/boost/regex.hpp:31, from /cygdrive/c/code/lib/re_0_02_0/re/reno_config.pimpl.h:10, from header-test.cpp:4: /cygdrive/c/code/lib/boost-trunk/boost/regex/v4/regex.hpp:140: error: `std::wstring' has not been declared /cygdrive/c/code/lib/boost-trunk/boost/regex/v4/regex.hpp:140: error: `const_iterator' was not declared in this scope /cygdrive/c/code/lib/boost-trunk/boost/regex/v4/regex.hpp:140: error: template argument 1 is invalid /cygdrive/c/code/lib/boost-trunk/boost/regex/v4/regex.hpp:140: error: template argument 2 is invalid /cygdrive/c/code/lib/boost-trunk/boost/regex/v4/regex.hpp:140: error: ISO C++ forbids declaration of `wsmatch' with no type In file included from /cygdrive/c/code/lib/boost-trunk/boost/regex/v4/regex.hpp:151, from /cygdrive/c/code/lib/boost-trunk/boost/regex.hpp:31, from /cygdrive/c/code/lib/re_0_02_0/re/reno_config.pimpl.h:10, from header-test.cpp:4: /cygdrive/c/code/lib/boost-trunk/boost/regex/v4/regex_iterator.hpp:172: error: `std::wstring' has not been declared /cygdrive/c/code/lib/boost-trunk/boost/regex/v4/regex_iterator.hpp:172: error: `const_iterator' was not declared in this scope /cygdrive/c/code/lib/boost-trunk/boost/regex/v4/regex_iterator.hpp:172: error: template argument 1 is invalid /cygdrive/c/code/lib/boost-trunk/boost/regex/v4/regex_iterator.hpp:172: error: template argument 2 is invalid /cygdrive/c/code/lib/boost-trunk/boost/regex/v4/regex_iterator.hpp:172: error: template argument 3 is invalid /cygdrive/c/code/lib/boost-trunk/boost/regex/v4/regex_iterator.hpp:172: error: ISO C++ forbids declaration of `wsregex_iterator' with no type In file included from /cygdrive/c/code/lib/boost-trunk/boost/regex/v4/regex.hpp:154, from /cygdrive/c/code/lib/boost-trunk/boost/regex.hpp:31, from /cygdrive/c/code/lib/re_0_02_0/re/reno_config.pimpl.h:10, from header-test.cpp:4: /cygdrive/c/code/lib/boost-trunk/boost/regex/v4/regex_token_iterator.hpp:286: error: `std::wstring' has not been declared /cygdrive/c/code/lib/boost-trunk/boost/regex/v4/regex_token_iterator.hpp:286: error: `const_iterator' was not declared in this scope /cygdrive/c/code/lib/boost-trunk/boost/regex/v4/regex_token_iterator.hpp:286: error: template argument 1 is invalid /cygdrive/c/code/lib/boost-trunk/boost/regex/v4/regex_token_iterator.hpp:286: error: template argument 2 is invalid /cygdrive/c/code/lib/boost-trunk/boost/regex/v4/regex_token_iterator.hpp:286: error: template argument 3 is invalid /cygdrive/c/code/lib/boost-trunk/boost/regex/v4/regex_token_iterator.hpp:286: error: ISO C++ forbids declaration of `wsregex_token_iterator' with no type Emil Dotchevski Reverge Studios, Inc. http://www.revergestudios.com/reblog/index.php?n=ReCode