Support for USER_HEADER in build system #233
Conversation
|
Great addition. Thanks. I suppose the Customizing BridgeStan part of the doc? With a link to the CmdStan User's Guide. Any idea why the Rust tests failed? |
|
Rust tests try to load all the modules from the folder, so I think we just need to exclude this the same way we exclude syntax_error. Customizing BridgeStan is probably the best section, though it's more per-model that most of the other recommendations there |
|
Let me know when you are ready for me to look this over again. Thanks. |
|
@roualdes I think it's ready for another look! |
|
|
||
| Namely, you can declare a function in your Stan model and then define it in a separate C++ file. | ||
| This requires passing the ``--allow-undefined`` flag to the Stan compiler when building your model. | ||
| The :makevar:`USER_HEADER` variable must point to the C++ file containing the function definition. |
There was a problem hiding this comment.
Should we say explicitly that it should be a C++ header file? We only reference it being a .hpp file in the makevar variable name and the example file name.
There was a problem hiding this comment.
It technically does not need to be a header (or even a .hpp, in theory a .txt would also work, since the compiler is just pasting it in), as long as it's code that can be included into the model's translation unit it would be fine.
Personally I think the name USER_HEADER is evocative enough
This ports the portion of the CmdStan makefile that allows for easier inclusion of external C++ functions:
https://mc-stan.org/docs/cmdstan-guide/external_code.html
Essentially, if the
--allow-undefinedoption is passed to stanc3, we then look for a header file to be included during compilation. By default this isuser_header.hppin the same folder as the Stan model, but it can be changed by settingUSER_HEADER.I'm not sure where is the best place to slot in documentation for this.