C# in Depth, Fourth Edition

Chapter 13. Improving efficiency with more pass by reference

This chapter covers

• Aliasing variables with the ref keyword
• Returning variables by reference with ref returns
• Efficient argument passing with in parameters
• Preventing data changes with read-only ref returns, read-only ref locals, and read-only struct declarations
• Extension methods with in or ref targets
• Ref-like structs and Span<T>

When C# 7.0 came out, it had a couple of features that struck me as slightly odd: ref local variables and ref returns. I was slightly skeptical about how many developers would need them, as they seemed to be targeted situations involving large value types, which are rare. My expectation was that only near-real-time services and games ...