[gen740]

Summary

• Add a standalone bench/ CMake project comparing cli20, CLI11, argparse, cxxopts, and Boost.Program_options.
• Add runtime, binary size, stripped size, allocation count, and hyperfine compile-time benchmarks.
• Run benchmark reports for both C++20 and C++26 via nix build .#bench.
• Expand many_options to include string, int, double, path, and enum-like conversions.

User-Facing API Changes

• Token::position now uses std::size_t to avoid truncating argv positions.
• TokenizeResult keeps tokenizer storage configurable through CLI20_TOKEN_STACK_CAPACITY.
• tokenize() now accepts option_nargs / is_command callables instead of prebuilt spec maps.
• parse_or_exit output overloads are split into stdio and iostream headers so parser.hh avoids iostream output.
• TokenizerConfig remains non-owning, but prefix/separator customization now uses StringLiteral template arguments to avoid dangling views.
• Description remains non-owning and now accepts string literals only; runtime-owned descriptions should be represented by a separate explicit owning API if needed.

Validation

• nix develop -c cmake --build build-bench
• BENCH_CXX_STANDARD=26 nix develop -c cmake --build build-bench/cxx26
• BENCH_CXX_STANDARD=26 nix develop -c bench/scripts/run-runtime.sh --benchmark_filter=Simple --benchmark_min_time=0.01s
• nix build -L .#bench
• nix run .#build

[Copilot]

Pull request overview

This PR introduces a standalone benchmark suite (runtime, size, and compile-time) for comparing cli20 against several other C++ CLI libraries, and wires the generated results into the documentation site. To support more meaningful allocation/size measurements, it also refactors parts of the parser/tokenizer and removes std::format usage from several core headers.

Changes:

• Add a bench/ CMake project plus scripts to run runtime/size/compile-time benchmarks and summarize/export results.
• Add documentation UI (React component + CSS + MDX page) to display benchmark results from a generated JSON dataset.
• Refactor tokenizer/config/token storage and parse_or_exit output handling to reduce dependencies (notably std::format) and support benchmarking.

Reviewed changes

Copilot reviewed 74 out of 75 changed files in this pull request and generated 7 comments.

Show a summary per file

File	Description
tests/test_tokenize.cc	Updates tokenize test harness to new lookup-based tokenize API and prefix accessor helper.
tests/compile_pass/token_stack_capacity.cc	Adds compile-pass coverage for CLI20_TOKEN_STACK_CAPACITY override.
tests/CMakeLists.txt	Adds try_compile-based compile-pass tests.
include/cli/parser.hh	Refactors tokenizer API, token prefix representation, small-vector token storage, and parse_or_exit output behavior.
include/cli/parser_stdio.hh	Adds parse_or_exit overload using FILE* destinations.
include/cli/parser_iostream.hh	Adds parse_or_exit overload using iostream destinations.
include/cli/help.hh	Removes std::format usage in help text generation.
include/cli/cli.hh	Simplifies umbrella include to parser.hh only.
include/cli/argument.hh	Changes Description representation (now string_view) to reduce dependency/size.
include/cli/action.hh	Replaces std::format-based formatting with to_chars/stream-based formatting for error subjects/messages.
flake.nix	Adds Nix packaging for benchmark dependencies and a bench build target/app.
examples/custom_action.cc	Removes std::formatter example and adjusts output formatting accordingly.
docs/src/data/benchmarks/results.json	Adds benchmark result dataset consumed by docs UI.
docs/src/css/custom.css	Adds styling for benchmark charts/table UI.
docs/src/components/BenchmarkCharts.jsx	Adds React component to render benchmark charts and a detailed results table.
docs/sidebars.ts	Adds “benchmarks” page to docs sidebar.
docs/docs/benchmarks.mdx	Adds benchmarks documentation page embedding the new charts component.
docs/docs/actions.mdx	Updates docs example strings to remove std::format usage.
bench/size/subcommand/cxxopts.cc	Adds size benchmark case implementation for cxxopts (subcommand).
bench/size/subcommand/cli20.cc	Adds size benchmark case implementation for cli20 (subcommand).
bench/size/subcommand/cli11.cc	Adds size benchmark case implementation for CLI11 (subcommand).
bench/size/subcommand/boost.cc	Adds size benchmark case implementation for Boost.Program_options (subcommand).
bench/size/subcommand/argparse.cc	Adds size benchmark case implementation for argparse (subcommand).
bench/size/simple/cxxopts.cc	Adds size benchmark case implementation for cxxopts (simple).
bench/size/simple/cli20.cc	Adds size benchmark case implementation for cli20 (simple).
bench/size/simple/cli11.cc	Adds size benchmark case implementation for CLI11 (simple).
bench/size/simple/boost.cc	Adds size benchmark case implementation for Boost.Program_options (simple).
bench/size/simple/argparse.cc	Adds size benchmark case implementation for argparse (simple).
bench/size/many_options/cxxopts.cc	Adds size benchmark case implementation for cxxopts (many_options).
bench/size/many_options/cli20.cc	Adds size benchmark case implementation for cli20 (many_options).
bench/size/many_options/cli11.cc	Adds size benchmark case implementation for CLI11 (many_options).
bench/size/many_options/boost.cc	Adds size benchmark case implementation for Boost.Program_options (many_options).
bench/size/many_options/argparse.cc	Adds size benchmark case implementation for argparse (many_options).
bench/size/CMakeLists.txt	Adds CMake targets for building size benchmark executables across cases/libraries.
bench/scripts/summarize.py	Adds benchmark report generator producing Markdown tables from result artifacts.
bench/scripts/run-size.sh	Adds script to build size targets, strip binaries, and emit TSV results.
bench/scripts/run-runtime.sh	Adds script to build and run Google Benchmark runtime suite and emit JSON results.
bench/scripts/export-doc-data.py	Adds script to normalize runtime/size/compile-time results into docs JSON schema.
bench/runtime/subcommand.cc	Adds runtime benchmarks (and allocation measurement) for subcommand schema.
bench/runtime/simple.cc	Adds runtime benchmarks (and allocation measurement) for simple schema.
bench/runtime/many_options.cc	Adds runtime benchmarks (and allocation measurement) for many_options schema.
bench/runtime/CMakeLists.txt	Adds runtime benchmark executable target linking required libs.
bench/runtime/allocation_count.cc	Overrides global new/delete to count allocations during benchmarks.
bench/results/.gitkeep	Keeps results directory present in the repo.
bench/results/.gitignore	Ignores generated benchmark artifacts under bench/results/.
bench/include/bench/many_options.hh	Adds shared types/helpers for many_options benchmark schema.
bench/include/bench/argv.hh	Adds shared argv storage/helper for benchmarks.
bench/include/bench/allocation_counter.hh	Adds allocation counting utilities integrated with Google Benchmark counters.
bench/compile_time/scripts/run.sh	Adds hyperfine-driven compile-time benchmark runner producing TSV/JSON outputs.
bench/compile_time/scripts/compile-one.sh	Adds script to compile one case/library TU into an object for timing.
bench/compile_time/cases/subcommand/cxxopts.cc	Reuses size benchmark source for compile-time measurements (subcommand/cxxopts).
bench/compile_time/cases/subcommand/cli20.cc	Reuses size benchmark source for compile-time measurements (subcommand/cli20).
bench/compile_time/cases/subcommand/cli11.cc	Reuses size benchmark source for compile-time measurements (subcommand/cli11).
bench/compile_time/cases/subcommand/boost.cc	Reuses size benchmark source for compile-time measurements (subcommand/boost).
bench/compile_time/cases/subcommand/argparse.cc	Reuses size benchmark source for compile-time measurements (subcommand/argparse).
bench/compile_time/cases/simple/cxxopts.cc	Reuses size benchmark source for compile-time measurements (simple/cxxopts).
bench/compile_time/cases/simple/cli20.cc	Reuses size benchmark source for compile-time measurements (simple/cli20).
bench/compile_time/cases/simple/cli11.cc	Reuses size benchmark source for compile-time measurements (simple/cli11).
bench/compile_time/cases/simple/boost.cc	Reuses size benchmark source for compile-time measurements (simple/boost).
bench/compile_time/cases/simple/argparse.cc	Reuses size benchmark source for compile-time measurements (simple/argparse).
bench/compile_time/cases/many_options/cxxopts.cc	Reuses size benchmark source for compile-time measurements (many_options/cxxopts).
bench/compile_time/cases/many_options/cli20.cc	Reuses size benchmark source for compile-time measurements (many_options/cli20).
bench/compile_time/cases/many_options/cli11.cc	Reuses size benchmark source for compile-time measurements (many_options/cli11).
bench/compile_time/cases/many_options/boost.cc	Reuses size benchmark source for compile-time measurements (many_options/boost).
bench/compile_time/cases/many_options/argparse.cc	Reuses size benchmark source for compile-time measurements (many_options/argparse).
bench/CMakeLists.txt	Adds top-level bench CMake project wiring runtime + size subdirs.
bench/cmake/BenchLibraries.cmake	Adds CMake helper libraries and dependency discovery for benchmark builds.
.gitignore	Adds build-bench/ to ignored build artifacts.
.github/workflows/windows-unicode.yml	Updates checkout action version used in CI workflow.
.github/workflows/release.yml	Updates checkout action version used in release workflow.
.github/workflows/release-docs.yml	Updates checkout action version used in docs release workflow.
.github/workflows/docs-preview.yml	Updates checkout action version used in docs preview workflow.
.github/workflows/deploy-nightly-docs.yml	Updates checkout action version used in nightly docs deploy workflow.
.github/workflows/ci.yml	Updates checkout action version used in main CI workflow.
.github/workflows/bump-version.yml	Updates checkout action version used in bump-version workflow.

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

[Copilot]

Pull request overview

Copilot reviewed 74 out of 75 changed files in this pull request and generated 9 comments.

Comments suppressed due to low confidence (1)

include/cli/cli.hh:4

• cli/cli.hh no longer includes cli/argument.hh, but the repository still has code (e.g. bench/size/many_options/cli20.cc) that includes <cli/cli.hh> and uses cli::StringOption/cli::Arg, which will fail to compile. Either restore #include "cli/argument.hh" in this umbrella header, or update all consumers to include cli/argument.hh explicitly (and consider documenting the change since it’s a breaking include-level API change).