Boost logo

Boost :

Subject: Re: [boost] Is there any interest in a dependency injection library?
From: Sohail Somani (sohail_at_[hidden])
Date: 2014-07-28 10:48:13

On 2014-07-27, 5:46 PM, Kris wrote:
> Hi Sohail,
>> So that example is fine when it comes to a single type, but I have
>> hundreds of types that are separately compiled. Creating an injector for
>> each type is cumbersome. Is there a way you can come up with a solution
>> that is generic? I know you suggested type lists but that is too much of
>> a burden.
> 3) mixed runtime/compile time solution, which, at some point, I made
> proof-of-concept of, but I did give up on in the end, due to the fact I
> wasn't able to get compile time checking working in many cases, runtime
> overhead and implementation complexity didn't help either - anyway such
> solution might be easily implemented on top of current library,
> proof-of-concept and the idea might be found in:
> di::injector<> injector;
> injector.install(
> di::bind<interface, implementation>()
> );
> injector.install(
> di::bind<int>::to(42)
> );
> injector.create<app>();
> Thanks:) Anyway IMHO runtime binding may have some abilities of static
> checking, but exceptions will have to be thrown there either way. Separately
> compiling bindings definitely might be achieved with static checking for
> example with usage of forward declarations or composition root approach.

It doesn't need to do the fancy stuff, though it is (almost?) all
possible in my experience. Somehow, Guice survives by detecting things
at runtime so I would take from their experience that it is not a
completely terrible proposition. Is it possible to automatically convert
a static injector to a dynamic one? This might be the best of both
worlds. That is, something like this:

SomeModule() {
   return di::make_injector(

I think you have all the information you need to do this. I'd encourage
you to continue to develop the "dynamic" portion in a way that you're
happy with it. Personally, I'd be happy if the above worked.


Boost list run by bdawes at, gregod at, cpdaniel at, john at