c# - 使用呼叫计数器创建功能

Question

问题很简单：如何使调用代码尽可能简单？我的代码有点愚蠢，但我看不到。

using System;

namespace ConsoleApplication48
{
class FunctionWithCounter<T, TResult>
{
    private readonly Func<T, TResult> function;
    public int Calls { get; private set; }

    private FunctionWithCounter(Func<T, TResult> function)
    {
        Calls = 0;
        this.function = function;
    }

    public static implicit operator FunctionWithCounter<T, TResult>(Func<T, TResult> func)
    {
        return new FunctionWithCounter<T, TResult>(func);
    }

    public TResult this[T arg]
    {
        get
        {
            Calls++;
            return function(arg);
        }
    }
}

class Program
{
    static void Main()
    {
        FunctionWithCounter<double, double> func = (Func<double, double>)(x => x*x);
        for (int i = 0; i < 5; i++)
        {
            double d = func[i];
        }
        Console.WriteLine(func.Calls);
        Console.ReadKey();
    }
}
}

所以我使用索引器来调用这样的 func[x] 而不是 func(x)，并且有一些困难（不能像 void 方法那样调用）。但我认为这是最简单的。有什么优惠吗？

Answer 1

对于 1 额外行的价格，我会将其恢复到至少正常的函数语法。还要摆脱隐式构造函数，它并不能真正为您节省任何东西，没有它，语法看起来更简单。

class FunctionWithCounter<T, TResult>
{
    public readonly Func<T, TResult> Function;
    public int Calls { get; private set; }

    public FunctionWithCounter(Func<T, TResult> function)
    {
        Calls = 0;
        Function = x =>
            {
                Calls++;
                return function(x);
            };
    }        
}

internal class Program
{
    private static void Main(string[] args)
    {
        var callCounter = new FunctionWithCounter<double,double>(x => x * x);
        var func = callCounter.Function;

        for (int i = 0; i < 5; i++)
        {
            double d = func(i);
        }
        Console.WriteLine(callCounter.Calls);
        Console.ReadKey();
    }
}