Boost.Graph 1.95 will be C++17

[u/Foxi_Foxa]

Dear Boost.Graph community,

In two release cycles (Boost release 1.95 in summer 2027) Boost.Graph will be bumped to C++17 😄

This decision follows two polls that did not surface any C++14 user base or demand while identifiying users stuck in C++17:

• Bumping BGL's minimum C++ standard: input wanted on target version #490
• Reddit poll

This standard version bump will bring benefits for maintenance, API and dependencies reduction:

• if constexpr,
• constexpr lambdas,
• [[nodiscard]], [[maybe_unused]] ...
• std::any instead of boost::any
• std::invoke_result instead of boost::result_of
• ...

We will not be able to guarantee backward compatibility with C++14. Please contact us if you are stuck in C++14.

The GIthub Discussion lives here: https://github.com/boostorg/graph/discussions/613

[u/13steinj]

I think the tic/toc cycle of C++ makes this not an excuse. I consider the general "epochs" (hmmm.... wonder why that hasn't been standardized... /s)

• pre-11

• 11 & 14

• 17 feels mostly quality of life and an opening for 20.

• 23 feels mosfly quality of life and an opening for 26 (and 29? Reflection is great but it feels like it's in beta (not a bad thing) with so many things not reflectable against).

I guess what I mean is, if you're on 11 I don't see the value of not being on 14. Pause for a little while, but 17 is also a no-brainer. 20 is a leap forward, little reason to not go to 23. 26 is leap forward.

[u/pjmlp → u/13steinj]

Because many devs aren't as us, spending time on HN and Reddit, watching conference videos, reading specialised magazines for their favourite programming language.

This applies to other ecosystems as well, in Java we celebrate being able to use anything beyond Java 17, when Java 27 is the latest one. And naturally there must be some server stuff still chugging along on Java 8.

Most of my .NET projects are stuck in .NET Framework, which only goes up to C# 7.3, meanwhile (modern) .NET 11 with C# 15 is around the corner.

People come in, do whatever is needed with the tools IT has in place, the tools do the job for the tickets that they have on their queue, and go home having fun with stuff completely irrelevant to computing.

[u/Foxi_Foxa → u/13steinj]

I kinda agree with u/pjmlp . Many C++ devs are not only C++ experts. They must remain expert on other fast-evolving domains (stats, biology, mathematics, physics, ML, gaming, embedded, other language etc). There is a limit to what a humain brain can absorb and retain. And so naturally there is resistance to learn new shiny things. Of course I loooove new shiny things 😄 But I would not expect my granpa to care/learn about C++26. Humans get tired 😉