Quinton Miller

For standard library specs we could consider using something like this in as many places as possible: https://github.com/crystal-lang/crystal/blob/98c091ee9dd5a0e75b3dd47b642bd170b4c84a39/spec/std/big/big_rational_spec.cr#L8-L23

Another concrete example is implementing the `throw_info` primitive, used for exception handling on Windows, in plain code: https://github.com/crystal-lang/crystal/blob/401eb47bf373f11b2da6e382c306ead36615e1d6/src/compiler/crystal/codegen/primitives.cr#L1338 ```crystal lib LibC $type_info_vtable = "\u{1}??_7type_info@@6B@" : Void* end ```

Duplicate of #12624 (this is not exclusive to Windows by the way)

If you add `require "big"` to the prelude, but then comment out the top-level call to `LibGMP.set_memory_functions` in `src/big/lib_gmp.cr`, the same would actually happen as soon as you call `1.to_big_i`...

While I fully agree with this, if a `--single-module` build still takes many minutes to run, is there any extra progress indication we could show?

Related: #10036 If autocasting is applied recursively, we should be able to do this too: ```crystal Foo.new [1_u8] # okay, UInt8 literal is compatible with Int32 here so # the...

Let's say we now devirtualize `Foo+` to `Foo`. How would we define a `ReferenceStorage` that can hold a `Foo` or any subclass then? Here we could safely initialize a `Foo`...

I suppose you could theoretically do this for `Foo+` if `ReferenceStorage` were an extern type: ```crystal @[Extern(union: true)] struct FooPlus @base = uninitialized ReferenceStorage(Foo) {% for t, i in Foo.all_subclasses...

Now I am thinking of the opposite: if `ReferenceStorage(Foo)` can hold `Foo` or any of its subclasses, is it possible at all to obtain the storage for just `Foo` in...

On POSIX environments you can probably pass `LLVM_CONFIG=true` to suppress all the default configuration too (the Makefiles can be easily adjusted for this).