解决方案在.NET泛型重载运算约束 [英] Solution for overloaded operator constraint in .NET generics

问题描述

我会做什么，如果我想有只接受已重载操作类型，例如减法运算符的通用方法。我试图用一个接口作为约束，但接口不能有运算符重载。

What would I do if I want to have a generic method that only accepts types that have overloaded an operator, for instance the subtraction operator. I tried using an interface as a constraint but interfaces can't have operator overloading.

什么是实现这一目标的最佳途径？

What is the best way to achieve this?

推荐答案

有没有直接的答案;运营商是静态的，并且不能在约束pssed前$ P $ - 和现有primatives不实现任何特定的接口（对比IComparable的并[d T＆GT;]，它被用来模拟大于/小于）

There is no immediate answer; operators are static, and cannot be expressed in constraints - and the existing primatives don't implement any specific interface (contrast to IComparable[<T>] which can be used to emulate greater-than / less-than).

不过，如果你只是希望它的工作，然后在.NET 3.5有一些选项...

However; if you just want it to work, then in .NET 3.5 there are some options...

我在这里把一个图书馆 ，允许运营商高效和简单的访问泛型 - 如：

I have put together a library here that allows efficient and simple access to operators with generics - such as:

T result = Operator.Add(first, second); // implicit <T>; here

可以下载为 MiscUtil

此外，在C＃4.0，这通过动态成为可能：

Additionally, in C# 4.0, this becomes possible via dynamic:

static T Add<T>(T x, T y) {
    dynamic dx = x, dy = y;
    return dx + dy;
}

我也有（在一个点）的.NET 2.0版，但毕竟是少的测试。另一种选择是创建一个接口，如

I also had (at one point) a .NET 2.0 version, but that is less tested. The other option is to create an interface such as

interface ICalc<T>
{
    T Add(T,T)() 
    T Subtract(T,T)()
}

等等，但你需要传递一个 ICalc＆LT;通过了所有的方法T＆GT ;; ，它就会变得混乱

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