rust_win32_sample

An exercise in directly exercising winapi-rs for fun and profit.

Why

• "0" dependencies (well, minus winapi-rs of course)
• I'll want to do interop with existing C++ rendering pipelines someday for middleware
• bgfx-rs shows that even just maintaining C++ builds is as painful as always, why not try a pure 100% Rust stack?

Takeaways

1. Using winapi-rs's COM interop is nicer than expected (mostly thanks to powerful macro codegen).
2. Dealing with winapi-rs 's explosion of modules is an exercise in annoyance. Fortunately this is something of a one-time cost, since I can simply collapse them back into a single module: src\win32.rs
3. RLS intellisense doesn't work on COM interfaces. Probably because of all the macros. Boo! I've been keeping a copy of winapi-rs open in another VS Code instance and Ctrl+Shift+Fing through the source instead.
4. Default rust panic/assert behavior is lame, doesn't even breakpoint on the correct source line. Especially annoying for multithreaded work (bgfx-rs), where panics noop until rethrown from thread.join(). Easy to write your own expect!(...) macros, although trailing .unwrap!() might not be possible.
5. winapi-rs COM interfaces practice interior mutability (all methods are implemented vs &self).
6. Hygenic macros are hygenic. Specifically, a macro can apparently return [a, b, c] (single AST node?) but not a, b, c. Error messages for early versions of input_layout! were quite opaque before I realized this.
7. Lack of StaticMutex or lazy_static! in stable stdlib gets annoying fast for shared internal resources like win32 WNDCLASS registration, but can be worked around with manual AtomicUsize spinlocks and the like.
8. Directly using winapi-rs is mostly an exercise in wrapping everything in unsafe { ... }.