Rust - can I ask/force compiler to do monomorphization code generation while compiling a crate (instead of postponing it to the caller crate )

Question

I have project that build with cargo workspace with including lot of crates.

One of the lower level crates contains generic data-structure with a lot of serde-code involved.

In order to reduce the compile time , I tried to crate objects with monomorphized instances on the the data-struct in a crate that is lower in the compilation hierarchy and use those in the higher-level crates. My goal to compile the lower-level crate only once, and then work on the higher level crate - without generating the monomorphized instances every time.

example:

lower-level crate
----------------- 

pub struct MyCache<T> {
    //generic implementation of cache  
}  

pub struct MyCacheString {
    cache: MyCache<String> 
} 

higher-level crate
------------------
use MyCacheString; 

but the problem is that the compiler generated that monomorphized in the higer-level crate (according to "cargo llvm-lines")

Is there is a way to ask/force the compiler to generate the monorphized code while it's compile the lower level crate?

Answer 1

ok, according to rustc_monomorphize::collector docstring:

Lazy mode means that items will only be instantiated when actually referenced

So in order to tigger the compiler to monomorphized the code in the low-level crate I need to call the object functions from public non-generic function lower-level crate. (not sure why - but it's not working from async function).

(If someone know about macro that tell the compiler to use the 'Eager Mode' it's will be better )