1.1 KiB
1.1 KiB
[namespace.future]
16 Library introduction [library]
16.4 Library-wide requirements [requirements]
16.4.5 Constraints on programs [constraints]
16.4.5.2 Namespace use [namespace.constraints]
16.4.5.2.3 Namespaces for future standardization [namespace.future]
Top-level namespaces whose namespace-name consists of std followed by one or more digits ([lex.name]) are reserved for future standardization.
The behavior of a C++ program is undefined if it adds declarations or definitions to such a namespace.
[Example 1:
The top-level namespace std2 is reserved for use by future revisions of this International Standard.
â end example]