Re: [boost] Re: First lambda

From: Shannon Stewman (stew_at_[hidden])
Date: 2004-03-09 18:06:15

On Tue, Mar 09, 2004 at 03:32:02PM +0100, Gabriel Dos Reis wrote:
> David Abrahams <dave_at_[hidden]> writes:

<snip>

> |       labmbda x,y: x+y
> | 
> | It'd be nice if we could get to something that simple.
> 
> Yes, and it is one the simplest common cases. The correspnding
> formulation in C++ would be as simple as well, e.g.
> 
>     (auto x, auto y) { x + y; }
> 
> (three months ago, Bjarne showed another candidate: { x, y; | x + y; })
> 
>   The main issue in this discussion, however, concerns what to do when
> a reference is made to an automatic variable in an enclosing scope.

Older versions of python do this:

    z = 155
    fxn = lambda x, y=z: x+y
    fxn(2)   # returns 157

In seem to remember that newer versions have a form of closuring.

How about:

   int z = 155;
   (auto x, auto y=z) { x + y; }

It's not the greatest syntax, and it's often pretty annoying, but I
think it's a tad more readable than the proposed.

Best,

-- 
Shannon Stewman         | Let us walk through the waning night,
Caught in a whirlpool,  | As dawn-rays tickle our toes, the dew soothes
A quartering act:       | Our blistered soles, and damp bones stir
Solitude or society?    | As crimson cracks under the blue-grey sky.