Annex C (informative) Compatibility [diff]

Affected: [library] – [exec]

Change: New reserved identifiers.

Rationale: Required by new features.

Effect on original feature: Valid C++ 2003 code that uses any identifiers added to the C++ standard library by later revisions of C++ may fail to compile or produce different results in this revision of C++.

A comprehensive list of identifiers used by the C++ standard library can be found in the Index of Library Names in this document.

Change: New headers.

Rationale: New functionality.

Effect on original feature: The following C++ headers are new: <array>, <atomic>, <chrono>, <condition_variable>, <forward_list>, <future>, <initializer_list> ([initializer.list.syn]), <mutex>, <random>, <ratio>, <regex>, <scoped_allocator>, <system_error>, <thread>, <tuple>, <typeindex> ([type.index.synopsis]), <type_traits>, <unordered_map>, and <unordered_set>.

In addition the following C compatibility headers are new: <cfenv>, <cinttypes>, <cstdint>, and <cuchar>.

Valid C++ 2003 code that #includes headers with these names may be invalid in this revision of C++.

Change: Function swap moved to a different header.

Rationale: Remove dependency on <algorithm> for swap.

Effect on original feature: Valid C++ 2003 code that has been compiled expecting swap to be in <algorithm> may have to instead include <utility>.

Change: New reserved namespace.

Rationale: New functionality.

Effect on original feature: The global namespace posix is now reserved for standardization.

Valid C++ 2003 code that uses a top-level namespace posix may be invalid in this revision of C++.

Change: Additional restrictions on macro names.

Rationale: Avoid hard to diagnose or non-portable constructs.

Effect on original feature: Names of attribute identifiers may not be used as macro names.

Valid C++ 2003 code that defines override, final, carries_dependency, or noreturn as macros is invalid in this revision of C++.