In this final part of the tuple-iteration mini-series, we move beyond C++20 and C++23 techniques to explore how C++26 finally brings first-class language support for compile-time iteration. With structured binding packs (P1061) and expansion statements (P1306), what once required clever template tricks can now be written in clean, expressive, modern C++.

C++ Templates: How to Iterate through std::tuple: C++26 Packs and Expansion Statements

by Bartlomiej Filipek

From the article:

In part 1 of this mini-series, we looked at the basics of iterating over a std::tuple using index_sequence and fold expressions. In part 2, we simplified things with std::apply and even created helpers like for_each_tuple and transform_tuple.

So far, we used C++ features up to C++20/23… but now, in C++26, we finally get language-level tools that make tuple iteration straightforward and expressive. In this article, we’ll explore two new techniques:

• Structured bindings can introduce a pack - P1061 - turn a tuple into a pack of variables.
• Expansion statements P1306 - the ultimate “compile-time loop” syntax.