TartanLlama/expected

Health v2 · maintenance only

Adoption not part of the score

1879 stars · 161 forks observed · 2026-08-28

What it is AI-extracted, prompt v1, taxonomy v1, 2026-08-30, confidence not recorded

A single-header C++11/14/17 implementation of std::expected with functional-style extensions like map, and_then, and or_else. It lets developers represent values that either succeed or carry error information and chain fallible computations cleanly.

Use cases

• represent success-or-error return values in C++ without exceptions
• chain fallible computations with monadic composition
• backport std::expected to C++11/14/17 projects
• replace verbose error-checking code with map/and_then pipelines
• handle parse results with typed error reasons

When to choose

• you need std::expected semantics on pre-C++23 compilers
• you want a dependency-free single-header error handling utility
• you prefer functional-style error propagation over exceptions or error codes

When to avoid

• your toolchain already ships std::expected (C++23)
• you want a full-fledged result/error framework with rich diagnostics
• your codebase style mandates exceptions for error handling

Facets

library · maturity stable

error-handling developer-tools developer-tools programming-languages cpp cross-platform single-header std-expected functional-programming c++11 header-only algorithms

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