🚀 Zero-Copy Strings
Substring creates new string (allocation). Span slices without copying.
// ❌ Allocates memory
string text = "Hello, World!";
string hello = text.Substring(0, 5); // New string
// ✅ Zero allocation
ReadOnlySpan span = text.AsSpan();
ReadOnlySpan hello = span.Slice(0, 5); // No copy!
// Parsing without allocation
ReadOnlySpan numbers = "123,456,789".AsSpan();
var parts = numbers.Split(',');
Performance: 100x less GC pressure in tight loops.
Use Cases: Parsing, string manipulation in hot paths, high-performance servers.