h3 VS Oat++

It looks like the base Kontur dataset uses H3 resolution 8, and there’s a lookup table here. “400m” seems to refer to the edge length (which averages to 461m).

I can speak to quadtrees, but the primary reason for using this is that you need a geographic "dictionary" (not using the word map to avoid confusion with charts), and you're perhaps already using the H3 hexagonal grid system.

HexSet: is a way of storing a set of H3 cells in a tree, and doing fast (2-20 ns on my 2013 trashcan Mac Pro) membership tests. You must first convert the input data (e.g. GeoJSoN polygon) into H3 cells.

> What an amazing tool that can completely change function names when it converts from C to Go.

How can one read the code of the benchmark, then switch into virulent sarcasm mode without trying to understand the code? And seeing "+1" comments without any effort to understand is also disheartening.

The blog post had a link about the Go helper functions the author used. It lands on https://github.com/akhenakh/goh3/blob/main/h3.go This shows that the `FromGeo()` function used by the Go benchmark is a helper that calls transpiled functions. The benchmark code itself was of course not transpiled, so the sarcasm was unneeded and wrong.

If anyone wants to dig in deeper, the C function `latLngToCell()` calls 2 functions, see https://github.com/uber/h3/blob/master/src/h3lib/lib/h3Index...

Uber just released their library to perform geospatial indexing - https://h3geo.org/. This might be an useful building block for you.

I looked at oatpp and drogon, which are both great, but feel too high-level for my purposes. I tried drogon and got something working, but it feels like too much for my requirements, as in particular I'd like to slot in my choice of Json and message-body handling. C.f. the simple approach in Crow, which I easily understand and build on.

With the right libraries, C++ could be a good fit for applications that want to expose a fast web API to things that need lots of compute (simulators, for instance) or I/O (interactive editing of large datasets). Projects like Oat++ and Crow give me hope that we might see such an ecosystem develop.

Lots of other options have been mentioned, but I'll throw Oat++ into the mix. I used it for this purpose and it was reasonably painless.

https://github.com/oatpp/oatpp +WASM ;)

cd "some/temp/path/for/repositories" git clone https://github.com/oatpp/oatpp.git cd oatpp mkdir build && cd build cmake .. (sudo) make install

Maybe use something like https://oatpp.io to create a REST API: C++ in the backend with this library to create a REST server, and the JavaScript/TypeScript frontend to ask for the information.

I've used OATPP ( https://github.com/oatpp/oatpp ) which worked nicely for setting up simple rest interfaces. Supports things like swagger & websockets out of the box. It's also on Conan which is nice if you use cmake. I can't speak to it's performance but it has about a 1mb binary size footprint.

As for your web problem, I have only used https://oatpp.io/ in the past but I'm sure there are more frameworks like that on the internet.