[miki123211]

Can you even make the standard library dynamically linked in the C way??

In C, a function definition usually corresponds 1-to-1 to a function in object code. In Rust, plenty of things in the stdlib are generic functions that effectively get a separate implementation for each type you use them with.

If there's a library that defines Foo but doesn't use VecFoo>, and there are 3 other libraries in your program that do use that type, where should the Vec functions specialized for Foo reside? How do languages like Swift (which is notoriously dynamically-linked) solve this?

[zozbot234]

You can have an intermediate dynamic object that just exports Vec<Foo> specialized functions, and the three consumers that need it just link to that object. If the common need for Vec<Foo> is foreseeable by the dynamic object that provides Foo, it can export the Vec<Foo> functions itself.