Do you know ref struct?

ref struct in C# is a special type of structure that is guaranteed to be allocated on the stack, not on the heap. Such structures cannot be copied or stored on the heap, which enhances safety and performance when working with unsafe code or large amounts of data.

Main features of ref struct:

• Cannot implement interfaces.
• Cannot be used in async methods (as they can be deferred and moved to the heap).
• Used, for example, in Span<T>, which allows working with contiguous memory segments without allocations.

Example declaration:

ref struct MyRefStruct
{
    public int Value;
}

void Process()
{
    MyRefStruct s = new MyRefStruct { Value = 10 };
    // s lives on the stack and cannot be stored on the heap
}