David B. Held wrote:
> In this code,
>
> template <class F, typename T>
> struct apply_lambda
> {
> typedef typename mpl::lambda<F>::type f_;
> typedef typename mpl::apply<f_, T>::type type;
> };
>
> MSVC reports that there is no "apply" in "mpl". I thought
> it was being stupid, so I preprocessed the source, and
> verified that sure enough there *is* no apply in mpl.
That's correct (see lines 58-62 in "boost/mpl/apply.hpp"). One have to use
the numbered forms, and it's a recommended practice for writing portable MPL
code. The same with 'bind' (for slightly different reasons, but still).
> I discovered that apply1 works just fine, however. I assume
> that MSVC can't handle the full apply<> machinery,
It can, but it doesn't like the name clash between top-level 'apply'
template and nested 'apply'-s inside metafunction classes:
template< typename F, typename T >
struct apply
{
typedef T type;
};
struct her
{
template< typename T > struct apply // ICE here
{
typedef T type;
};
};
Renaming top-level 'apply' to something else (e.g. 'apply_') resolves the
conflict, but IMO it's not worth it - you can use the appropriate numbered
form to the same effect.
> but is this documented?
Now it is :). Speaking seriously, it's on my documentation to-do list.
Aleksey
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