Annex C (informative) Compatibility [diff]

C.4 C++ and ISO C++ 2014 [diff.cpp14]

C.4.7 [library]: library introduction [diff.cpp14.library]

Affected subclause: [headers]
Change: New headers.

Rationale: New functionality.

Effect on original feature: The following C++ headers are new: <any> ([any.synop]), <charconv> ([charconv.syn]), <execution> ([execution.syn]), <filesystem> ([fs.filesystem.syn]), <memory_­resource> ([mem.res.syn]), <optional> ([optional.syn]),
<string_­view> ([string.view.synop]), and <variant> ([variant.syn]).
Valid C++ 2014 code that #includes headers with these names may be invalid in this International Standard.
Affected subclause: [namespace.future]
Change: New reserved namespaces.

Rationale: Reserve namespaces for future revisions of the standard library that might otherwise be incompatible with existing programs.

Effect on original feature: The global namespaces std followed by an arbitrary sequence of digits are reserved for future standardization.
Valid C++ 2014 code that uses such a top-level namespace, e.g., std2, may be invalid in this International Standard.