Console.WriteLine() 错误 CS1503 无法从“void”转换为“bool”

Question

I am executing this simple program in which I am trying to see the outcome of Console.WriteLine with function returning void given as an argument.

using System;

class Program
{
    static void printMe()
    {
    }

    static void Main(string[] args)
    {
        Console.WriteLine(printMe());
    }
}

This is giving following error:

Program.cs(11,27): error CS1503: Argument 1: cannot convert from 'void' to 'bool' [C:\Users\Nafeez Quraishi\source\repos\X\X.csproj]

The build failed. Fix the build errors and run again.

As per the WriteLine documentation at https://docs.microsoft.com/en-us/dotnet/api/system.console.writeline?view=netframework-4.8 this looks to be corresponding to following case:

WriteLine(Object)

Writes the text representation of the specified object, followed by the current line terminator, to the standard output stream.

Question is:

In order to write text representation of the function object returning void, why is it trying to covert it in to bool(than perhaps string)?

Answer 1

the void is treated specially by C# language and .net runtime. so a user can not create an instance of void by static way or dynamic way.

Now come to your question about why it converts into bool and not in the string.

if you run below code in unsafe assembly. you can see it has size of 1 byte. this lead to convert into bool and not string

        static unsafe void Main(string[] args)
    {
        //Console.WriteLine(sizeof(System.Void));
        var o = System.Runtime.Serialization.FormatterServices.GetUninitializedObject(typeof(void));
        Console.WriteLine(System.Runtime.InteropServices.Marshal.SizeOf(o));
        Console.Read();
        //Console.WriteLine(System.Runtime.InteropServices.Marshal.SizeOf(System.Void));
    }

Answer 2

How do you print one void (obviously means 'void'-nothing, not even null)? You must return something, not 'void'

If you want, you can do

static bool!!!!! printMe() //Hi I'm a function returning a value, bool precisely.
{
    return false; //I must return something.
}

Edit: you want the signature of the function/method? You want Reflection. https://docs.microsoft.com/en-us/dotnet/csharp/programming-guide/concepts/reflection

static void Main()
{
    MethodInfo[] mInfo= typeof(TheClass).GetMethods();
    //now you can enumerate the methods, and know everything about them, even run them
}

Welcome to new way to use C#, there are so many space, get in.