Ever wondered why your clean, object-oriented design sometimes slows things down? This piece breaks down how virtual dispatch impacts performance—and how techniques like devirtualization and static polymorphism can eliminate that overhead entirely.

Devirtualization and Static Polymorphism

by David Álvarez Rosa

From the article:

Ever wondered why your “clean” polymorphic design underperforms in benchmarks? Virtual dispatch enables polymorphism, but it comes with hidden overhead: pointer indirection, larger object layouts, and fewer inlining opportunities.

Compilers do their best to devirtualize these calls, but it isn’t always possible. On latency-sensitive paths, it’s beneficial to manually replace dynamic dispatch with static polymorphism, so calls are resolved at compile time and the abstraction has effectively zero runtime cost.