d解包为指针

原文
可这样:

template Includes(Args...)
{
   template Recurse(Arg...)
   {
      import std.meta: AliasSeq;
      static if (1 == Arg.length)
        alias Recurse = AliasSeq!(Arg[0]*);
      else
        alias Recurse = AliasSeq!(Arg[0]*, Recurse!(Arg[1..$]);
   }

   alias Includes = Includes!(Args);
}
void view_it(Args...)(void function(entity_t, Includes!(Args) cb)) {...}

可以用静映射,这里把每个类型变成指针.

import std.meta;

alias Args = AliasSeq!(int, string, double);
struct Includes { alias args = Args; }
struct entity_t {}

alias PointerTo(T) = T*;//指针

void view_it(void function(entity_t, staticMap!(PointerTo, Includes.args) ) cb)
{
    // 干活.
}

但是,不会在view_it模板原始代码中工作,因为参数列表中有staticMap,会阻止编译器自动推导模板参数.
因此,这里,最好使回调类型全泛化,并用模板约束来强制执行要求:

import std.meta: allSatisfy;
import std.traits: isPointer;

void view_it(Callback)(Callback cb)
    if (
        is(Callback == void function(entity_t, Args), Args...)
        && allSatisfy!(isPointer, Args)
    )//约束
{
    // 干活
}

这里是引用