Jens Gustedt

Modern C, Second Edition

A new edition of the book Modern C and much more are now available under a CC license via the following page This edition is the result of a collaboration with Manning, and improves a lot over the…

The C23 edition of Modern C

The C23 edition of Modern C is now available for free download from And as before a dedicated page for the book may be found at where you also may find a link to download the code examples that com…

Defer available in gcc and clang

About a year ago I posted about defer and that it would be available for everyone using gcc and/or clang soon. So it is probably time for an update. Two things have happened in the mean time: A tec…

The provenance memory model for C

[The wordpress markdown inclusion does a very bad job, it seems, there have been some idiotic formatting errors. I hope that these are fixed, now.] A years-long effort led by Kayvan Memarian and Pe…

A Defer Mechanism for C

An overview of a paper that presents a reference implementation of a defer mechanism (co-authored with Robert C. Seacord) has been accepted for publication at SAC’21. The full version is avai…

C2x: the next real revision of the C standard

C: Simple Defer, Ready to Use

With this post I will concentrate on the here and now: how to use C’s future lifesaving defer feature with existing tools and compilers.

Modern C is now feature complete

You find the latest version of my book at the usual place at This now contains all the material that I plan to put into it. New are “experience” parts about performance, function-like m…

Contracts for C

C++ seems to finally converge with their contracts proposal, I decided to give it a try and come up with ideas how such a thing would look for C. This is in early stages, not a full proposal yet, a…

White space does matter in C23

Usually in C identifiers are not directly followed by strings. But when U prefixed literals were introduced in C. there still were some rare clashes with existing code. This happened were a macro U…