使用从位置m开始的Arg ...的n个参数 [英] Using n arguments from Args... starting from position m

问题描述

说我有不同的函数，它们有可变数量的参数。第一个参数总是通过其他方式获得的指针。所有其他参数我使用模板包扩展通过另一个模板获得。

我用于调用这些函数的模板如下：

Say I have different functions, which have a variable number of arguments. The first argument is always a pointer obtained through other means. All other arguments I obtain through another template using template pack expansion.
Template that I use for calling these functions is as follows:

template<typename RT, typename... Args>
inline RT call(RT(*function)(Args...))
{
    return function(pointer_from_somewhere, bind_argument<Args>::get_arg()...);
}

这显然不会编译，因为它执行所有参数的模板扩展，

由于我总是通过其他方式获取第一个参数，我将如何对进行模板包扩展sizeof ...（Args） - 1 参数，从第二个参数开始？

This obviously doesn't compile, as it performs template expansion for all arguments, thus there being too many arguments.
Since I always obtain the first argument through other means, how would I do template pack expansion for sizeof...(Args) - 1 arguments, starting from the 2nd argument?

EDIT：

为了演示的目的，它可能是相关的，第一个参数（指针）是reinterpret_cast总是对第一个参数的类型。我使用 std :: tuple_element< 0，std :: tuple< Args ...>> :: type 找出第一个参数的类型。

$ b

While the template is slimmed down for demonstration purposes, it might be relevant, that the 1st argument (the pointer) is reinterpret_cast'ed always to the type of first argument. I use std::tuple_element<0, std::tuple<Args...>>::type for finding out the type of the 1st argument.

推荐答案

这是您要查找的吗？

template<typename RT, typename A0, typename... Args>
inline RT call(RT(*function)(A0, Args...))
{
    return function(pointer_from_somewhere, bind_argument<Args>::get_arg()...);
}

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