Why i cannot declaring stackalloc MyStr[10] when MyStr is 'ref struct'

[P9avel]

I am want putting all in stack. But my code not compiled. I dont undetstand why.

public ref struct MyStr
{
public int I { get; set; }
}

internal class Program
{
static void Main(string[] args)
{
Span arr = stackalloc MyStr[10];

    MyStr ms = new MyStr()
    {
        I = 123
    };

    Console.WriteLine("Hello, World!");
}

}

Can you describe?

[gfoidl]

Because MyStr is used as type argument for T in Span<T>, and ref structs are not allowed as type arguments.

You could

• MyStr* a = stackalloc MyStr[10];
• use [InlineArray] (.NET 8)

to work around this.