- added as part of C# 7.2.
- defined with
ref struct StructName - always on the stack
- never part of heap
- cannot be element of an array
- cannot be field type of reference type
- can’t implement interfaces
- can’t be boxed
- can’t be type argument
- can’t be captured by closure of lambda or local function
- can’t be used in async methods
- can’t be used in iterators
Further read:
https://learn.microsoft.com/en-us/dotnet/csharp/language-reference/builtin-types/ref-struct