A deep dive into C# Span<T> and ReadOnlySpan<T>, covering how they work as stack-only ref structs that provide allocation-free views over contiguous memory. Includes practical examples of slicing strings and arrays, BenchmarkDotNet results showing a 38% speed improvement and zero heap allocations versus string.Split, and an explanation of the managed pointer internals that make Span<T> fast. Also covers limitations (no async, no class fields), when to use Memory<T> instead, and .NET Framework compatibility via the System.Memory NuGet package.
Table of contents
Understanding Span<T>C# Programming with Span<T>Span<T> APIsImproving some C# code performance with Span<T>Explanations About the Magic Behind Span<T> ImplementationFrequently Asked Questions about Span<T>Conclusion487 Impressions