C++ Small Vector Optimization: Boost small_vector vs LLVM SmallVector vs Folly small_vector vs Abseil InlinedVector

Mon, 29 Jun 2026 00:00:00 +0000

Introduction

The Small Vector Optimization (SVO) — also known as Small Buffer Optimization (SBO) — is one of the most impactful performance patterns in C++ systems programming. The insight is simple: most vectors in real-world programs contain very few elements (often 0-8). Rather than allocating heap memory for every vector, SVO libraries embed a small stack-allocated buffer directly inside the container object, only falling back to heap allocation when the element count exceeds the inline capacity.

Small-Vector on Pi Stack

C++ Small Vector Optimization: Boost small_vector vs LLVM SmallVector vs Folly small_vector vs Abseil InlinedVector

Introduction