C# Feature - Interpolated string handlers
Overview
Section titled “Overview”Interpolated string handlers let an API control how interpolation is built, which can skip allocations when the consumer decides the message is not needed.
Introduced In
Section titled “Introduced In”C# 10.0 (2021)
Example
Section titled “Example”logger.LogDebug($"User {userId} loaded in {elapsedMs} ms");Why It Matters
Section titled “Why It Matters”The call-site syntax stays the same, but C# 10 lets the target API receive the interpolation through a custom handler instead of always building a string first.
Gotchas & Best Practices
Section titled “Gotchas & Best Practices”- This feature mainly matters for library and framework authors.
- Most application developers use it indirectly through logging and diagnostics APIs.