Elstl

Elstl is a name used for several lightweight, STL-inspired libraries aimed at C++ development in resource-constrained environments. It denotes efforts to replicate the feel of the Standard Template Library while reducing footprint. There is no single official specification or canonical implementation.

Historically, elstl emerged as developers sought portable templates and containers suitable for embedded systems. Multiple independent projects adopted the elstl label, resulting in a family of implementations rather than a unified project.

Design and features commonly found in elstl projects include container templates resembling vectors, lists, and maps, along with a set of algorithms and iterators. Emphasis is placed on small memory usage, predictable performance, and configurable memory management via custom allocators. Many variants are distributed as header-only libraries to simplify integration and compilation.

Compatibility and limitations vary across implementations. Because elstl projects differ in scope, they rarely provide complete compatibility with the full STL. Some offer STL-like semantics with restrictions, while others present simplified interfaces tailored to specific toolchains. Trade-offs often include limited exception support, reduced RTTI, or fewer standard library dependencies.

Usage and reception of elstl libraries are most common in embedded programming, robotics, and other environments where standard library support is inadequate. They occupy a niche between portability and performance, and they are less standardized than the official STL. Prospective users typically evaluate maturity, portability, licensing, and ecosystem compatibility before adopting an elstl solution.