# libc++ C++1Y Status

In April 2013, the C++ standard committee approved the draft for the next version of the C++ standard, known as "C++1Y" (probably to be C++14)

The draft standard includes papers and issues that were voted on at the previous three meetings (Kona, Portland, and Bristol)

This page shows the status of libc++; the status of clang's support of the language features is here.

The groups that have contributed papers:

- CWG - Core Language Working group
- LWG - Library working group
- SG1 - Study group #1 (Concurrency working group)

### Paper Status

Paper # | Group | Paper Name | Meeting | Status | First released version
--- | --- | --- | --- | --- | ---
3346 | LWG | Terminology for Container Element Requirements - Rev 1 | Kona | Complete | 3.4
3421 | LWG | Making Operator Functors greater<> | Portland | Complete | 3.4
3462 | LWG | std::result_of and SFINAE | Portland | Complete | 3.4
3469 | LWG | Constexpr Library Additions: chrono, v3 | Portland | Complete | 3.4
3470 | LWG | Constexpr Library Additions: containers, v2 | Portland | Complete | 3.4
3471 | LWG | Constexpr Library Additions: utilities, v3 | Portland | Complete | 3.4
3302 | LWG | Constexpr Library Additions: complex, v2 | Portland | Complete | 3.4
3545 | LWG | An Incremental Improvement to integral_constant | Bristol | Complete | 3.4
3644 | LWG | Null Forward Iterators | Bristol | Complete | 3.4
3668 | LWG | std::exchange() | Bristol | Complete | 3.4
3658 | LWG | Compile-time integer sequences | Bristol | Complete | 3.4
3670 | LWG | Addressing Tuples by Type | Bristol | Complete | 3.4
3671 | LWG | Making non-modifying sequence operations more robust | Bristol | Complete | 3.4
3656 | LWG | make_unique | Bristol | Complete | 3.4
3654 | LWG | Quoted Strings | Bristol | Complete | 3.4
3642 | LWG | User-defined Literals | Bristol | Complete | 3.4
3655 | LWG | TransformationTraits Redux (excluding part 4) | Bristol | Complete | 3.4
3657 | LWG | Adding heterogeneous comparison lookup to associative containers | Bristol | Complete | 3.4
3672 | LWG | A proposal to add a utility class to represent optional objects | Bristol | Removed from Draft Standard | n/a
3669 | LWG | Fixing constexpr member functions without const | Bristol | Complete | 3.4
3662 | LWG | C++ Dynamic Arrays (dynarray) | Bristol | Removed from Draft Standard | n/a
3659 | SG1 | Shared Locking in C++ | Bristol | Complete | 3.4
3779 | LWG | User-defined Literals for std::complex | Chicago | Complete | 3.4
3789 | LWG | Constexpr Library Additions: functional | Chicago | Complete | 3.4
3924 | LWG | Discouraging rand() in C++14 | Issaquah | Complete | 3.5
3887 | LWG | Consistent Metafunction Aliases | Issaquah | Complete | 3.5
3891 | SG1 | A proposal to rename shared_mutex to shared_timed_mutex | Issaquah | Complete | 3.5

### Library Working group Issues Status

Issue # | Issue Name | Meeting | Status
--- | --- | --- | ---
1214 | Insufficient/inconsistent key immutability requirements for associative containers | Kona | Complete
2009 | Reporting out-of-bound values on numeric string conversions | Kona | Complete
2010 | is_* traits for binding operations can't be meaningfully specialized | Kona | Complete
2015 | Incorrect pre-conditions for some type traits | Kona | Complete
2021 | Further incorrect usages of result_of | Kona | Complete
2028 | messages_base::catalog overspecified | Kona | Complete
2033 | Preconditions of reserve, shrink_to_fit, and resize functions | Kona | Complete
2039 | Issues with std::reverse and std::copy_if | Kona | Complete
2044 | No definition of "Stable" for copy algorithms | Kona | Complete
2045 | forward_list::merge and forward_list::splice_after with unequal allocators | Kona | Complete
2047 | Incorrect "mixed" move-assignment semantics of unique_ptr | Kona | Complete
2050 | Unordered associative containers do not use allocator_traits to define member types | Kona | Complete
2053 | Errors in regex bitmask types | Kona | Complete
2061 | make_move_iterator and arrays | Kona | Complete
2064 | More noexcept issues in basic_string | Kona | Complete
2065 | Minimal allocator interface | Kona | Complete
2067 | packaged_task should have deleted copy c'tor with const parameter | Kona | Complete
2069 | Inconsistent exception spec for basic_string move constructor | Kona | Complete
2096 | Incorrect constraints of future::get in regard to MoveAssignable | Kona | Complete
2102 | Why is std::launch an implementation-defined type? | Kona | Complete
2071 | std::valarray move-assignment | Portland | Complete
2074 | Off by one error in std::reverse_copy | Portland | Complete
2081 | Allocator requirements should include CopyConstructible | Portland | Complete
2083 | const-qualification on weak_ptr::owner_before | Portland | Complete
2086 | Overly generic type support for math functions | Portland | Complete
2099 | Unnecessary constraints of va_start() usage | Portland | Complete
2103 | std::allocator_traits<std::allocator<T>>::propagate_on_container_move_assignment | Portland | Complete
2105 | Inconsistent requirements on const_iterator's value_type | Portland | Complete
2110 | remove can't swap but note says it might | Portland | Complete
2123 | merge() allocator requirements for lists versus forward lists | Portland | Complete
2005 | unordered_map::insert(T&&) protection should apply to map too | Portland | Complete
2011 | Unexpected output required of strings | Portland | Complete
2048 | Unnecessary mem_fn overloads | Portland | Complete
2049 | is_destructible is underspecified | Portland | Complete
2056 | future_errc enums start with value 0 (invalid value for broken_promise) | Portland | Complete
2058 | valarray and begin/end | Portland | Complete
2091 | Misplaced effect in m.try_lock_for() | Bristol | Complete
2092 | Vague Wording for condition_variable_any | Bristol | Complete
2093 | Throws clause of condition_variable::wait with predicate | Bristol | Complete
2094 | duration conversion overflow shouldn't participate in overload resolution | Bristol | Complete
2122 | merge() stability for lists versus forward lists | Bristol | Complete
2128 | Absence of global functions cbegin/cend | Bristol | Complete
2145 | error_category default constructor | Bristol | Complete
2147 | Unclear hint type in Allocator's allocate function | Bristol | Complete
2148 | Hashing enums should be supported directly by std::hash | Bristol | Complete
2149 | Concerns about 20.8/5 | Bristol | Complete
2162 | allocator_traits::max_size missing noexcept | Bristol | Complete
2163 | nth_element requires inconsistent post-conditions | Bristol | Complete
2169 | Missing reset() requirements in unique_ptr specialization | Bristol | Complete
2172 | Does atomic_compare_exchange_* accept v == nullptr arguments? | Bristol | Complete
2080 | Specify when once_flag becomes invalid | Bristol | Complete
2098 | promise throws clauses | Bristol | Complete
2109 | Incorrect requirements for hash specializations | Bristol | Complete
2130 | missing ordering constraints for fences | Bristol | Complete
2138 | atomic_flag::clear ordering constraints | Bristol | Complete
2140 | notify_all_at_thread_exit synchronization | Bristol | Complete
2144 | Missing noexcept specification in type_index | Bristol | Complete
2174 | wstring_convert::converted() should be noexcept | Bristol | Complete
2175 | string_convert and wbuffer_convert validity | Bristol | Complete
2176 | Special members for wstring_convert and wbuffer_convert | Bristol | Complete
2177 | Requirements on Copy/MoveInsertable | Bristol | Complete
2185 | Missing throws clause for future/shared_future::wait_for/wait_until | Bristol | Complete
2187 | vector<bool> is missing emplace and emplace_back member functions | Bristol | Complete
2190 | ordering of condition variable operations, reflects Posix discussion | Bristol | Complete
2196 | Specification of is_*[copy/move]_[constructible/assignable] unclear for non-referencable types | Bristol | Complete
2197 | Specification of is_[un]signed unclear for non-arithmetic types | Bristol | Complete
2200 | Data race avoidance for all containers, not only for sequences | Bristol | Complete
2203 | scoped_allocator_adaptor uses wrong argument types for piecewise construction | Bristol | Complete
2207 | basic_string::at should not have a Requires clause | Bristol | Complete
2209 | assign() overspecified for sequence containers | Bristol | Complete
2210 | Missing allocator-extended constructor for allocator-aware containers | Bristol | Complete
2211 | Replace ambiguous use of "Allocator" in container requirements | Bristol | Complete
2222 | Inconsistency in description of forward_list::splice_after single-element overload | Bristol | Complete
2225 | Unrealistic header inclusion checks required | Bristol | Complete
2229 | Standard code conversion facets underspecified | Bristol | Complete
2231 | DR 704 removes complexity guarantee for clear() | Bristol | Complete
2235 | Undefined behavior without proper requirements on basic_string constructors | Bristol | Complete
2141 | common_type trait produces reference types | Chicago | Complete
2246 | unique_ptr assignment effects w.r.t. deleter | Chicago | Complete
2247 | Type traits and std::nullptr_t | Chicago | Complete
2085 | Wrong description of effect 1 of basic_istream::ignore | Chicago | Complete
2087 | iostream_category() and noexcept | Chicago | Complete
2143 | ios_base::xalloc should be thread-safe | Chicago | Complete
2150 | Unclear specification of find_end | Chicago | Complete
2180 | Exceptions from std::seed_seq operations | Chicago | Complete
2194 | Impossible container requirements for adaptor types | Chicago | Complete
2013 | Do library implementers have the freedom to add constexpr? | Chicago | Complete
2018 | regex_traits::isctype Returns clause is wrong | Chicago | Complete
2078 | Throw specification of async() incomplete | Chicago | Complete
2097 | packaged_task constructors should be constrained | Chicago | Complete
2100 | Timed waiting functions cannot timeout if launch::async policy used | Chicago | Complete
2120 | What should async do if neither 'async' nor 'deferred' is set in policy? | Chicago | Complete
2159 | atomic_flag initialization | Chicago | Complete
2275 | Why is forward_as_tuple not constexpr? | Chicago | Complete
2284 | Inconsistency in allocator_traits::max_size | Chicago | Complete
2298 | is_nothrow_constructible is always false because of create<> | Chicago | Complete
2300 | Redundant sections for map and multimap members should be removed | Chicago | Complete
NB comment: GB9 | Remove gets from C++14 | Chicago | Complete
2135 | Unclear requirement for exceptions thrown in condition_variable::wait() | Issaquah | Complete
2291 | std::hash is vulnerable to collision DoS attack | Issaquah | Complete
2142 | packaged_task::operator() synchronization too broad? | Issaquah | Complete
2240 | Probable misuse of term "function scope" in [thread.condition] | Issaquah | Complete
2252 | Strong guarantee on vector::push_back() still broken with C++11? | Issaquah | Complete
2257 | Simplify container requirements with the new algorithms | Issaquah | Complete
2268 | Setting a default argument in the declaration of a member function assign of std::basic_string | Issaquah | Complete
2271 | regex_traits::lookup_classname specification unclear | Issaquah | Complete
2272 | quoted should use char_traits::eq for character comparison | Issaquah | Complete
2278 | User-defined literals for Standard Library types | Issaquah | Complete
2280 | begin / end for arrays should be constexpr and noexcept | Issaquah | Complete
2285 | make_reverse_iterator | Issaquah | Complete
2299 | Effects of inaccessible key_compare::is_transparent type are not clear | Issaquah | Complete
1450 | Contradiction in regex_constants | Issaquah | Complete
2003 | String exception inconsistency in erase. | Issaquah | Complete
2112 | User-defined classes that cannot be derived from | Issaquah | Complete
2132 | std::function ambiguity | Issaquah | Complete
2182 | Container::[const_]reference types are misleadingly specified | Issaquah | Complete
2188 | Reverse iterator does not fully support targets that overload operator& | Issaquah | Complete
2193 | Default constructors for standard library containers are explicit | Issaquah | Complete
2205 | Problematic postconditions of regex_match and regex_search | Issaquah | Complete
2213 | Return value of std::regex_replace | Issaquah | Complete
2258 | a.erase(q1, q2) unable to directly return q2 | Issaquah | Complete
2263 | Comparing iterators and allocator pointers with different const-character | Issaquah | Complete
2293 | Wrong facet used by num_put::do_put | Issaquah | Complete
2301 | Why is std::tie not constexpr? | Issaquah | Complete
2304 | Complexity of count in unordered associative containers | Issaquah | Complete
2306 | match_results::reference should be value_type&, not const value_type& | Issaquah | Complete
2308 | Clarify container destructor requirements w.r.t. std::array | Issaquah | Complete
2313 | tuple_size should always derive from integral_constant<size_t, N> | Issaquah | Complete
2314 | apply() should return decltype(auto) and use decay_t before tuple_size | Issaquah | Complete
2315 | weak_ptr should be movable | Issaquah | Complete
2316 | weak_ptr::lock() should be atomic | Issaquah | Complete
2317 | The type property queries should be UnaryTypeTraits returning size_t | Issaquah | Complete
2320 | select_on_container_copy_construction() takes allocators, not containers | Issaquah | Complete
2322 | Associative(initializer_list, stuff) constructors are underspecified | Issaquah | Complete
2323 | vector::resize(n, t)'s specification should be simplified | Issaquah | Complete
2324 | Insert iterator constructors should use addressof() | Issaquah | Complete
2329 | regex_match()/regex_search() with match_results should forbid temporary strings | Issaquah | Complete
2330 | regex("meow", regex::icase) is technically forbidden but should be permitted | Issaquah | Complete
2332 | regex_iterator/regex_token_iterator should forbid temporary regexes | Issaquah | Complete
2339 | Wording issue in nth_element | Issaquah | Complete
2341 | Inconsistency between basic_ostream::seekp(pos) and basic_ostream::seekp(off, dir) | Issaquah | Complete
2344 | quoted()'s interaction with padding is unclear | Issaquah | Complete
2346 | integral_constant's member functions should be marked noexcept | Issaquah | Complete
2350 | min, max, and minmax should be constexpr | Issaquah | Complete
2356 | Stability of erasure in unordered associative containers | Issaquah | Complete
2357 | Remaining "Assignable" requirement | Issaquah | Complete
2359 | How does regex_constants::nosubs affect basic_regex::mark_count()? | Issaquah | Complete
2360 | reverse_iterator::operator*() is unimplementable | Issaquah | Complete
2104 | unique_lock move-assignment should not be noexcept | Issaquah | Complete
2186 | Incomplete action on async/launch::deferred | Issaquah | Complete
2075 | Progress guarantees, lock-free property, and scheduling assumptions | Issaquah | Complete
2288 | Inconsistent requirements for shared mutexes | Issaquah | Complete

Last Updated: 25-Mar-2014