[ACCEPTED]-Cannot take the address of the given expression C# pointer-pointers

Accepted answer

Score: 12

Is the error on my side?

No; the error is 22 in the documentation you linked to. It 21 states:

fixed (char* p = str) { /*...*/ }  // equivalent to p = &str[0]

The comment is incorrect; as you 20 correctly note, it is not legal to take 19 the address of the interior of a string. It 18 is only legal to take the address of the 17 interior of an array.

The legal initializers 16 for a fixed statement are:

The address operator & applied to a variable reference.
An array
A string
A fixed-size buffer.

str[0] is not a variable 15 reference, because first, string elements 14 are not variables, and second, because this 13 is a call to an indexing function, not a 12 reference to a variable. Nor is it an array, a 11 string, or a fixed-size buffer, so it should 10 not be legal.

I'll have a chat with the documentation 9 manager and we'll see if we can get this 8 fixed in a later revision of the documentation. Thanks 7 for bringing it to my attention.

UPDATE: I 6 have spoken to one of the documentation 5 managers and they have informed me that 4 we have just passed the deadline for the 3 next scheduled revision of the documentation. The 2 proposed change will go in the queue for 1 the revision after next.

Score: 2

This doesn't work because you're trying 2 to access a string. If you change your code 1 to:

char[] mySentence = "Pointers in C#".ToCharArray();

fixed (char* start = &mySentence[0])
{
    char* p = start;

    do
    {
        Console.Write(*p);
    }
    while (*(++p) != '\0');
}

Console.ReadLine();

everything will work fine.

Score: 0

mySentence[0] returns a readonly single 1 character, you cannot get a pointer to that.

Use:

fixed(char* start = &mySentence)

instead.

Source: stackoverflow.com

[ACCEPTED]-Cannot take the address of the given expression C# pointer-pointers

C#: Wrapping one Enum inside another (ie. mirroring another enum/copying it...)

Is a C# list like a C++ list?

C# unsafe value type array to byte array conversions

char* to a string in C#

what is `int *userMask[3][4]` pointing to?

Are array of pointers to different types possible in c++?

Passing a parameter as a pointer in JavaScript

What is the meaning of "wild pointer" in C?

C pointers and the physical address

One-dimensional access to a multidimensional array: is it well-defined behaviour?