[diff.cpp14.library]

Affected subclause: [headers]

Change: New headers.

Rationale: New functionality.

Effect on original feature: The following C++ headers are new: <any>, <charconv>, <execution>, <filesystem>, <memory_resource>, <optional>,

<string_view>, and <variant>.

Valid C++ 2014 code that #includes headers with these names may be invalid in this revision of C++.

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 ([lex.name]) are reserved for future standardization.

Valid C++ 2014 code that uses such a top-level namespace, e.g., std2, may be invalid in this revision of C++.