Re: [boost-ext] DI questions

From: Niall Douglas (s_sourceforge_at_[hidden])
Date: 2021-02-21 18:12:40

On 21/02/2021 15:39, Peter Dimov via Boost wrote:
> Niall Douglas wrote:
> 
>> I'll be frank in saying that I don't believe the current proposed 
>> Boost.DI does this. Unless I and most other people here can be 
>> convinced otherwise, my personal current expectation is that the 
>> proposed Boost.DI will be rejected, but hopefully with ample feedback 
>> on what to do for a Boost.DI v2, assuming Kris has the stamina and will.
> 
> By the look of it, what's being submitted is already a v3, if not v4. 
> It's fairly obvious that (and how) the design has evolved from 
> runtime-based to compile-time, for instance.

My memory is that the C++ 14 edition from five years ago did both, and I 
don't see much difference now. I do agree it's gained the patina of 
production aging, which is a good thing.

> There's a lot of functionality there that has clearly been added to 
> address issues arising from practical use. I'll be surprised if, after 
> you ask a specific question, the library does not already have an answer 
> for it.

I _suspect_ that as well, but for me personally, the current 
introduction page and the current tutorial aren't doing it for me.

- The introduction page reads like a hectoring blog post on why you are 
designing your code all wrong. This does not leave a person feeling 
welcome, or drawn into reading more.

- By the end of the tutorial, I don't feel "bought in" to the design 
pattern. I think it's hard in a vocab library to generate buy in for a 
specific library, but I think by the end of the tutorial the reader 
ought to be bought into "something like this vocab library", typically a 
hand written clone by the reader. I would count the tutorial as 
successful if that is achieved.

This tutorial, it just somehow feels unfocused. It swings between 
telling me implementation specifics to hectoring me about my code being 
wrong to being simultaneously too hand holdy in parts, and too sweeping 
in others. I reach the end of the tutorial page not really sure whether 
this design pattern is useful to my problem, and not without a certain 
amount of confusion as to what all this is about anyway. And I'm someone 
who is a fan of inverted responsibility design patterns, and I irritate 
my work colleagues constantly with lots of "weird" inversions in the 
code I design, so I _ought_ to be an easy conversion.

I think I need to reach the end of that tutorial convinced that a real 
problem I encounter often is being solved here.

Niall