cpp-result

This header-only library provides a minimal and efficient Rust-like Result<T, E> for C++17. It has no dependencies and offers a simple, ergonomic API inspired by Rust.

See examples or documentation for full usages.

Building

CMake

cmake -S . -B build
cmake --build build

Meson

meson setup builddir
meson compile -C builddir

Tests

googletest required

CMake

ctest --test-dir build

Meson

meson test -C builddir

Benchmarks

google-benchmark required

Benchmarks are provided to compare the performance of exceptions, error code returns, and Result<T, E>. This is a straightforward approach that provides a quick overview of the different methods.

CMake

cmake --build build --target benchmark

Meson

meson test -C builddir --benchmark

Feature Control

cpp_result allows you to enable or disable groups of API features at compile time to reduce binary size or limit API surface.

• Global switch:
  CPP_RESULT_FEATURE_ALL (default: enabled)
  If enabled, all features are active unless overridden.

• Individual features:

  • CPP_RESULT_FEATURE_UNWRAP : Unwrap/expect helpers (unwrap, unwrap_err, expect, etc.)
  • CPP_RESULT_FEATURE_MAP : Map/map_err/map_or/map_or_else
  • CPP_RESULT_FEATURE_ANDOR : and_, and_then, or_, or_else
  • CPP_RESULT_FEATURE_INSPECT : inspect, inspect_err
  • CPP_RESULT_FEATURE_CONTAINS : contains, contains_err
  • CPP_RESULT_FEATURE_FLATTEN : flatten
  • CPP_RESULT_FEATURE_OPTIONAL : ok(), err() as std::optional

You can set these macros before including the header, or use the build system options (-DCPP_RESULT_FEATURE_* for CMake, -DCPP_RESULT_FEATURE_* for Meson).

Example (disable all except unwrap):

#define CPP_RESULT_FEATURE_ALL 0
#define CPP_RESULT_FEATURE_UNWRAP 1
#include <result.hpp>

See the header and API docs for details.

License

MIT