Unable to build on macOS 14

[mangerlahn]

Building this project on macOS 14 currently fails. The accompanying Xcode 15 supports a version of C++ that does not contain std::unary_function, a function used by boost 1.7x. This has been resolved with boost 1.8x, which can't be used here because it also breaks the build.

The fix suggested here worked, I just needed to add

add_compile_definitions(_LIBCPP_ENABLE_CXX17_REMOVED_UNARY_BINARY_FUNCTION)

to the CMakeLists.txt file. Another workaround would of course be to restore compatibility with boost 1.8x.

The second issue I encountered was, that for some reason multiple unused result and unused parameter warnings popped up. As they were treated as errors, the build failed. By modifying the CMakeLists.txt again I was able to build successfully.
I added

add_compile_options(-Wno-unused-result -Wno-unused-parameter)

I have little experience with all of this, that's why I post this as a bug report instead of a PR. Not sure if it would be better to fix the affected code.

[adriantabirta]

I have the same problem

[loweas]

I as well. First workaround helped (thank you!) but can't seem to work around the next one where I get unused-results.

[danpat]

I made a PR to suppress most of those problems in #6709 - it's nothing fancy, just marks some unused results as ... unused, to keep the compiler happy.

[mangerlahn]

This has been resolved by #6709, thanks a lot!