Build a cffi-able rdkit! Using the magic of cargo build scripts
Similar in spirit to rdkitcffi but you don't want to rely on magic .so files committed to a git repo. Use this crate and your computer will build rdkit, with all the right cmake definitions, from scratch.
RDKit is a C++ mega-library, full of cheminformatics wisdom. We don't want to rewrite RDKit in Rust and C++ is not a straight-forward integration
target. C++, from what I can tell, does not have a stable "application binary interface" (ABI), i.e., no stable cross-language calling convention.
And even if it did have a stable C++ ABI, rust doesn't appear to support any flavor of it.
So we instead rely on a RDKit C++ wrapper, part of the official rdkit project, called the RDKit CFFI, or c foreign function interface where
all C++ code, inheritance and all, is wrapped with flat C style functions. Good news, calling out to C is Rust's bread and butter and part of
its wonderfully infectious design. Read more about CFFI from the RDKit lead.
This CFFI is not a super popular build option of RDKIt, so I don't know if it's common among various operating system distributions. Rust to the rescue,
we can use build.rs and the easy to use cmake helper library to build RDKit with the RDK_BUILD_CFFI_LIB definition set. The helper library also makes
the output RDKit library pieces go to a discoverable spot for Rust programs.
The CFFI flavor of RDKit is still emitted as a dynamically loaded library so our Rust software will always need to "find" the RDKit library somewhere
on disk. I could not figure out how to create a .a variant of the library, which would be suitable for static linking. Until I can create a .a just be
aware it might be a pain to run the RDKit program outside of a carefully constructed cargo run ... invocation.