20 General utilities library [utilities]

20.3 Compile-time integer sequences [intseq]

20.3.1 In general [intseq.general]

The library provides a class template that can represent an integer sequence.
When used as an argument to a function template the template parameter pack defining the sequence can be deduced and used in a pack expansion.
[Note 1:
The index_­sequence alias template is provided for the common case of an integer sequence of type size_­t; see also [tuple.apply].
— end note]