libpq is thread-safe as of PostgreSQL 7.0, so long as no two threads attempt to manipulate the same PGconn object at the same time.

we arrived at the conclusion that the notion of a "C ABI" is somewhat of an existential question, because the C Standard does not define a C ABI, and currently our extern "C" does not even support all Standard C types, like long double and _Complex. And the C language can add new types, of course (it in fact did in C23, non-optionally, a new type that all compilers will now be expected to support in order to claim they support C23). Thus saying "superset of a C ABI" is slightly dubious. It may prove beneficial for this experiment to hammer down what we mean, anyways, when we say "C ABI", extern "C", and so on, because there is a definable meaning that we in-practice work with.

crABI could define a symbol naming scheme, to allow identifying symbols that use crABI. However, crABI must be compatible with languages that only support C FFI and do not have native crABI support, and which must thus reference the symbol via its name; therefore, crABI should not have a complex or non-obvious mangling scheme.

In the 1970s the publishers of TAOCP abandoned Monotype in favor of phototypesetting. Knuth became so frustrated with the inability of the latter system to approach the quality of the previous volumes, which were typeset using the older system, that he took time out to work on digital typesetting and created TeX and Metafont.[37]

If you need to nest so much maybe factor it out into a function