Up requirements of Boost and C++

[robe2]

Boost 1.56 is very old.

Right now our docs have

C and C++ compilers

• Compiling with Boost 1.56 up to Boost 1.74 requires C++ Compiler with C++03 or C++11 standard support
• Compiling with Boost 1.75 requires C++ Compiler with C++14 standard support

1.75 was introduced in 2019. I propose get rid of support of Boost < 1.75 and require C++14.

We already voted and now require C++17 for pgRouting 4.0

Also change the docs:

C and C++ compilers

• Minimum C++ for pgRouting is C++17
• Compiling with Boost 1.75 requires C++ Compiler with C++14 standard support

[ayushjariyal]

@robe2, I want to work on this issue. Could you please assign it to me?

[maanya-chauhan]

Hi @robe2, I’d like to work on this issue.

I reviewed the current build configuration and documentation. I found that C++17 is already enforced in CMakeLists.txt, while the minimum Boost version is still set to 1.56.0. The building requirements documentation also still references Boost 1.56–1.75 with older C++ standards and lists BGL >= 1.56.

If approved, I plan to:

1. Update the minimum Boost requirement in CMakeLists.txt from 1.56.0 to 1.75.0.
2. Review the repository for any remaining references or checks that assume Boost versions below 1.75.
3. Update the building requirements documentation to reflect Boost >= 1.75 and C++17 as the minimum C++ standard for pgRouting 4.0.
4. Review the BGL requirement and update it if necessary so that it is consistent with the new Boost requirement.
5. Verify that the relevant build/CI configuration is consistent with the new requirements.
6. Build and run the relevant tests to make sure the changes do not introduce regressions.

I’ll keep the changes focused on the requirements described in this issue and submit a PR once the changes have been verified.