Increment pointer of byte array in C#

Question

I have a byte[] data in which I don't need first element. Array is quiet big, so I don't want to copy it to another array (payload) as shown below.

Buffer.BlockCopy(data, 1, payload, 0, count);

In C++ I can just increment pointer of array to move poiner.

int main()
{
    char* data= "!Hello, World!";
    data++;
    std::cout << data<< std::endl;
}

This part of code prints "Hello, World!". How I can do the same in C#? Maybe to use unsafe code?

Use a span by slicing the array, data.Slice(1) will create a Span<byte> starting at index 1 of the array and ending at its last element. — Prime
– Prime, Commented Mar 25, 2021 at 7:53
You might need to cast the array as a Span<byte> first, I don't know if it's implied. So it should be ((Span<byte>)data).Slice(1);. This will not cause a copy it's essentially a safe pointer to the array. — Prime
– Prime, Commented Mar 25, 2021 at 7:57
also, indexing into a Span<T> should be as fast as indexing into an array, if efficiency matters. It is a direct pointer as opposed to ArraySegment<T> which stores a reference to the array and an offset/boundary. — Prime
– Prime, Commented Mar 25, 2021 at 8:02

JHBonarius · Accepted Answer · 2021-03-25 08:11:45Z

2

You can slice arrays in c#8 using [1..].

var data = new char[] {'!','H','e','l','l','o',' ','W','o','r','l','d','!'};
foreach(var ch in data[1..]) Console.Write(ch);
Console.WriteLine();

gives: Hello World!

answered Mar 25, 2021 at 8:11

JHBonarius

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Muntadhar Haydar · Accepted Answer · 2021-03-25 08:06:47Z

0

Arrays have immutable length, so either start your loops and whatnot from index 1 instead of 0 or copy it to another one

answered Mar 25, 2021 at 8:06

Muntadhar Haydar

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