Giovanni Piero Deretta wrote:
On Fri, Mar 28, 2008 at 9:56 PM, Eric Niebler <eric@boost-consulting.com> wrote:
David Abrahams wrote:
To start with, there's one very basic thing we won't be able to do: name template specializations that cannot be instantiated, like
vector<foo(bar)>
just for DSEL purposes.
Ugh! I suppose this would work around the issue:
vector<call<foo(bar)>>
as long as call<> happened to be Regular.
What about
template<class Wrapped<typename T...>, typename ArgList... > class bind;
bind<vector, foo(bar(_1)), _2>
That should work, even if 'Wrapped' requires it template arguments to conform to some exotic concept.
Really? It seems to me that this would effectively strip the requirements from a template, violating the metatype system. Can someone who knows, comment?
Or may be something like this:
bind<vector>(foo(bar(_1)), _2)
Untested of course, and I'm not sure how concepts interact with template template parameters.
Me neither. Doug? The question is whether this should compile in C++0x: // Takes an unconstrained template: template<template<typename T> class S> struct foo {}; // A constrained template template<Regular Value> struct vector {}; foo<vector> f; // OK? Prolly not. Sadly, it looks like because of concepts, in C++0x we're going to lose a lot of our cute MPL lambda-isms. :-( -- Eric Niebler Boost Consulting www.boost-consulting.com