They could then potentially end up spending more time testing every possible combination of input then they would spending compiling with a strongly typed language that prevents the invalid syntax from compiling to begin with…

Honestly, this is maybe the most telling about where OP is coming from… If not straight up flame baiting; that or they mistook /r/rustcirclejerk as a serious subreddit

The constraint on memory isn’t on the compiler it is in the available ram and flash on ultra-lowcost/power microcontrollers, use can find some with less than 1KByte of ram, so that 32bit int could have been 4 8bit ints in your electric toothbrush. The packing of bits is space effecient, but not compute effecient and takes several extra clock cycles to finish when run on an 8bit microcontroller. It’s better to store it in the native 8bit word size for these devices. Further more, on more powerful systems using the smaller size can allow you to optimize for SIMD instructions and actually do multiple operations per clock beyond what you could do with the 32bit size.

There are reasons for these types to exist; as was mentioned elsewhere, if you don’t care you can always just use i32 or i64 for your code and be done with it.

Soooo, an int in most architectures is actually signed, usually a 2’s compliment signed 32 bit value; but the spec does not require it to be 32bits, some platforms might use an 8 bit or 16bit value instead (think older 8bit microcontrollers). That’s why they have ‘int32_t’, ‘uint32_t’, etc for C/C++, it just sounds like you haven’t used these number types (check stdint.h). Rust just requires you to use the more explicit number format by default (which I personally prefer because I have had to jump between embedded and Linux development).

The multiple string types are annoying at first, but its probably better to realize that they are more like two types (String and str) with the apperstand (&) ones being references (think pointer in C/C++). A String is like a C++ std::string and a str is more like a C-String (fixed sized array ish of chars).

Enter embedded programming, believe it or not there is a ton of low level C code being written; also, try adding a new protocol for networking, there are many cases where bitstructure matters, I recently wrote a small bit of code for a project that used bit packing so that we could fit inside of a single Ethernet frame so that we didn’t have to deal with fragmentation and the networking overhead it caused.

For context, what is your past programming background and what are you trying to do? While rust is a great language, it may not be the right tool for what you’re trying to do if these are things that you view as unnecessary

A reason to not distribute a library as a binary is for cross platform support, this allows a library to technically be compiled and used in some other platform; with that said, there are assumptions about having the same system calls (or that the library only handles abstract things that don’t hook into a specific architecture), with that said, making cargo smarter and adding in the option to bundle some prebuilt libraries to be pulled for compatible platforms could speed some compile time (at the likely cost of build size, etc).

Distributing a library as source isn’t some weird rust paradigm, take BOOST for example, which is a large library for C++, and is usually distributed as source (but Linux distros may bundle prebuilt binaries; it is generally intended that you will compile it and use it as a shared library), actually a lot of compiled languages distribute their libraries as source, it also allows you to read their source if you need to see exactly how they’re doing something). I don’t believe there is anything preventing someone from using shared libraries in rust, although they do seem to be less common. Another reason to distribute a library as source is for licensing.

The unstable versioning… Ya, that is definitely annoying, and likely tied to the limited resources available for sustainment for various projects. With that said, compared to C/C++ many of these libraries are something that one might role their own or use in house libraries. Now for Tokio… You don’t have to use it for async, although you probably will want to (see: https://blog.poespas.me/posts/2024/05/24/rust-async-std-and-tokio-comparison/), I do wish there was a nice way to depend on a library and substitute some of its dependencies (aka Tokio); with that said, part of the cargo idea is that you don’t view these libraries as part of your source code for review (although, auditors would likely disagree, so acrediting with the inclusion of many in accredited libraries would probably not be fun)