[boost] [Fit] pipable order of the arguments

Subject: [boost] [Fit] pipable order of the arguments
From: Vicente J. Botet Escriba (vicente.botet_at_[hidden])
Date: 2015-10-05 20:52:48

Hi,

I would like to know what other think about the order of the pipe (See 
this issue https://github.com/pfultz2/Fit/issues/5).

What would be the expected meaning of

auto  r1 =1  | pipable(f)(2);

f(1,2) or f(2,1)?

What would be the expected meaning of

auto f2 = partial(f)(2);

auto  r1 =1  | pipable(f2);

f(1,2) or f(2,1)?

As the operator| has left-to-right associativity, we can not do

        auto x = 1 | 2 | pipable(f);

We would need a way to pack the parameters

        auto x = forward_as_tuple(1, 2) | pipable(f);

but this wouldn't compile as f has two parameters.

or use parenthesis

  auto x = 1 | (2 | pipable(f));

and the result will be f(2, 1).

Any ideas?

Best,
Vicente

Vicente