I briefly skimmed over the sources and noticed some things I'd like to get addressed. Unfortunately this is far from being a real comprehensive review as I would like it to be, due to time constraints. operator= should return non-const reference. I don't really like date_time::operator/() as a syntactic sugar for date_time::get() when the involved period is not period::year, but e.g. period::day_of_week_local. It raises eyebrows when first seeing it, forcing one to look at the documentation to find out what that overloaded operator means. BOOST_LOCALE_DECL needs to be defined in terms of BOOST_SYMBOL_EXPORT and BOOST_SYMBOL_IMPORT. Also the exception classes need to be attributed with BOOST_SYMBOL_VISIBLE (I assume all member functions of exception classes are defined inline, which appears to be the case). Many constructors should be explicit but aren't. Existence of standard C++11 features should be checked with BOOST_NO_XXX macros instead of BOOST_HAS_XXX. E.g. !defined BOOST_NO_CHAR16_T rather than defined BOOST_HAS_CHAR16_T. Boundary interface should seriously be reconsidered. I would like to see it be very much like that of regex_iterator and regex_token_iterator. Please replace throw with BOOST_THROW_EXCEPTION. For classes having a swap member function there should also be a free swap function found by ADL. 'int unused' parameters for post-in/decrement operators will trigger warnings, the parameter name better be removed. Functions using Boost.Locale facets under the hood (e.g. boost::locale::fold_case) should be documented as might throw std::bad_cast. boundary.hpp: line 311: s/continious/contiguous/ line 319: e-b might not be well-formed, use std::distance(b, e) line 338: s/collsion/collision/ date_time.hpp: line 936: t.time(v); should not be called unless in >> v; succeeded format.hpp: line 104: s/get_posision/get_position/ Also, shouldn't this be const? formatting.hpp: line 229: this is not exception-safe localization_backend.hpp: line 145: why not boost::scoped_ptr? shared/formatting.cpp: line 45: this is not exception-safe. Why not use copy-and-swap idiom? (it has no swap() currently, but I see no reason why there couldn't be) shared/mo_lambda.cpp: line 239: s/tockenizer/tokenizer/ encoding/codepage.cpp: Why are converter objects allocated on free store and not stack? icu/all_generator.hpp: What do //ok comments signify? posix/codecvt.cpp: lines 82, 85: needs changed to use RAII posix/converter.cpp: line 159: s/impl_std/impl_posix/ std/std_backend.cpp: line 229: s/impl icu/impl_std/ (noticed cases like this in some other files as well, not necessarily in std/) Gevorg P.S. I plan to submit my final review with vote in 7-8 hours time from now. I hope that is OK.