std :: initializer_list& lt;& gt;和参考参数 [英] std::initializer_list<> and a Reference Parameter

问题描述

我是使用初始化列表的新手，我想知道它们是否类似于其他stl容器.我的意思是说他们复制值吗?我正在尝试做的是一个简单的min()函数，如下所示:

I'm new to using initializer lists and I'm wondering if they work similar to other stl containers. By that I mean do they copy values? What I'm trying to do is a simple min() function like this:

template <class T> T& minArgs(const std::initializer_list<T&>& Arguments)
{
    const T* Smallest = Arguments.begin();
    for (const T* I = begin(Arguments); I != end(Arguments); ++I)
    {
        if (*I < *Smallest) Smallest = I;
    }
    return *Smallest;
}

但是，当我调用该函数时，我是从GCC获得的:

However when I call the function I get this from GCC:

error: 'const' qualifiers cannot be applied to 'int&'

我一直在玩这个游戏，似乎initializer_lists可能无法满足我的要求；我希望该函数也能排除非POD参数.va_list会是更好的选择吗?

I've been playing around with this and it seems initializer_lists may not do what I want; I want the function to except non-POD arguments as well. Would a va_list be a better alternative?

谢谢！

推荐答案

尝试时，出现这些错误.但是，当我摆脱了对引用的毫无意义的使用时，所有的方法都可以使用.

When I try it, I get these errors. Yet, when I get rid of your pointless use of references, it all works.

std :: initializer_list 存储值，而不是引用.您应该使用 const std :: initializer_list< T>& ，而不是 const std :: initializer_list< T&>& .

std::initializer_list stores values, not references. You should be taking a const std::initializer_list<T> &, not a const std::initializer_list<T&> &.

我要做的就是编写一个函数，该函数通过引用接受任意数量的参数，并返回对其中最大参数的引用.[...]使用initializer_lists是否可以?

All I'm trying to do is write a function that takes any number of arguments, by reference, and returns a reference to the largest of them. [...] Is this possible with initializer_lists?

不. std :: initializer_list 用于值，而不是引用.但是我看不出为什么您不能按价值而不是按引用来接受这些项目.或者，更重要的是，为什么不只使用 std :: min，它可以包含一个初始化列表?

No. std::initializer_list is for values, not references. But I see no reason why you couldn't take the items by value instead of by reference. Or, more to the point, why don't you just use std::min, which can take an initializer list?

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