Re: [Boost] [Lambda2] Review starts Monday March 22, 2021 to March 31, 2021

From: Phil Endecott (spam_from_boost_dev_at_[hidden])
Date: 2021-03-23 15:22:33

Rainer Deyke wrote:
> So here's my first impression.  It's simple, clean, and elegant. 
> However, it doesn't appear to solve any problem I have.  In a world 
> where C++ already has "real" lambda expressions as a language feature, 
> is there any need for another lambda library?
>
> I assume that the appeal of lambda2 is that it involves less typing. 

My impression is similar. I've just gone through my current codebase 
looking for lambdas that I could re-write using this syntax. Most can't, 
even the short ones, because I invoke functions or access members, and 
fn(_1) and _1.field aren't possible. Even when the placeholder form is 
possible, I lose my meaningful parameter names and possibly types.

Pre-C++11 I used to have code that used boost::lambda or similar, but 
I converted it all to use core language lambdas years ago. I guess that 
if there are people who still have code using boost::lambda, they may 
find that they can use lambda2 as a near drop-in replacement and maybe 
get faster compilation, or something. But I would suggest that they 
should grasp the nettle and update to just use core-language lambdas. 
Are there any cases where converting an old boost::lambda expression 
to a core-language lambda is particularly problematic?

Regards, Phil.