Re: Review Manager needed for Boost.Lambda2

From: Peter Dimov (pdimov_at_[hidden])
Date: 2020-09-08 19:31:19

Andrey Semashev wrote:

> Looking at the code, I wonder why there is "using namespace 
> std::placeholders". Shouldn't there be a separate namespace for 
> placeholders? (I also think, it goes against our header policies.)

This imports the placeholders into boost::lambda2. There is no scenario in 
which you want to make the operators available without the placeholders, so 
without this directive, you'd always need to use both

    using namespace boost::lambda2;
    using namespace std::placeholders;

This doesn't help anyone.

(Operators belong in the namespace of their arguments to be ADL-reachable, 
so ideally, they would have been in std::placeholders, but I obviously can't 
place them there.)