是否有可能使用.NET编写只接受数值类型的通用功能？ [英] Is it possible to write a generic function in .NET that only accepts numerical types?

问题描述

假设我想写这样一个函数如下（像往常一样，一个简单的例子，用于说明目的）：

Suppose I want to write a function like the following (as usual, a trivial example for illustrative purposes):

Public Function calcSqSum(Of T)(ByVal list As IEnumerable(Of T)) As T
    Dim sumSq As T

    For Each item As T In list
        sumSq += (item * item)
    Next

    Return sumSq
End Function

正如你可能已经猜到，此功能会导致一个错误，因为一个通用对象不能保证实施+运营商。据我所知，不过，任何数值类型（整数，双数，小数等）会的。

As you can probably guess, this function causes an error because a generic object is not guaranteed to implement the + operator. As far as I know, though, any numerical type (Integer, Double, Decimal, etc.) will.

有没有办法写一个（准）通用功能，可以接受任何的数字类型，而无需显式重载函数每个这种类型的自己呢？

Is there a way to write a (quasi-)generic function that can accept any numerical type, without having to explicitly overload the function for every such type yourself?

另外，我想同样可以接受的解决办法是，以某种方式检查一个类型实现了+操作​​符（或功能与数值类型一般关联并用于任何运营商）。

Alternatively, I suppose an equally acceptable solution would be to somehow check if a type implements the '+' operator (or any operator generally associated with numerical types and used by the function).

推荐答案

没有，因为没有具体的共同界面，所有这些工具。从本质上说，有一个在框架数字类型没有真正的概念。除非你包装在自定义的类，有你的方法，只接受你的类型（这是不是一个真正的直接回答你的问题，只是一种变通方法）。

No, since there's no specific common interface that all of them implement. In essence, there's no real notion of "numerical types" in the framework. Unless you wrap them in self-defined classes and have your method accept only your types (which is not really a direct answer to your question, just a workaround).

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