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Pull Request Overview
This PR upgrades the codebase to require C++20 as the minimum standard for extension builds. The change modernizes the codebase by replacing older C++17 constructs and string formatting approaches with C++20 features.
Key changes:
- Updates minimum C++ standard requirement from C++17 to C++20
- Replaces
std::ostringstreamstring formatting with C++20std::format - Modernizes template syntax using C++20
requiresclauses instead of SFINAE - Updates build configuration and CI workflows to use C++20
Reviewed Changes
Copilot reviewed 20 out of 20 changed files in this pull request and generated 3 comments.
Show a summary per file
| File | Description |
|---|---|
| CMakeLists.txt | Updates minimum C++ standard requirement from 17 to 20 |
| src/treespec/unflatten.cpp | Replaces ostringstream with std::format, adds std::span usage |
| src/treespec/treespec.cpp | Extensive modernization with std::format, std::span, std::ranges, and constinit |
| src/treespec/traversal.cpp | Updates string formatting to use std::format |
| src/treespec/serialization.cpp | Uses std::unordered_map::contains instead of find comparison |
| src/treespec/richcomparison.cpp | Replaces std algorithm calls with std::ranges equivalents |
| src/treespec/hashing.cpp | Uses std::unordered_map::contains for cleaner code |
| src/treespec/flatten.cpp | Comprehensive string formatting updates and template parameter renaming |
| src/treespec/constructors.cpp | String formatting modernization and std::ranges usage |
| src/registry.cpp | Updates string formatting and replaces PYBIND11_CONSTINIT with constinit |
| src/optree.cpp | String formatting updates and constinit usage |
| include/optree/treespec.h | Updates function signatures to use std::span and modernizes template parameters |
| include/optree/pytypes.h | Adds std::formatter specializations and modernizes template syntax with requires clauses |
| include/optree/pymacros.h | Replaces PYBIND11_CONSTINIT with constinit |
| include/optree/exceptions.h | Major refactoring using std::source_location and std::format for error handling |
| README.md | Updates documentation to reflect C++20 requirement |
| CPPLINT.cfg | Adds whitespace/braces filter |
| .github/workflows/tests.yml | Removes C++17 compatibility test |
| .github/workflows/lint.yml | Updates clang-tidy to use C++20 |
| .clang-format | Updates standard from c++17 to c++20 |
Codecov Report✅ All modified and coverable lines are covered by tests. Additional details and impacted files@@ Coverage Diff @@
## main #235 +/- ##
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Coverage 100.00% 100.00%
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Files 14 14
Lines 1416 1416
Branches 175 175
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Code reviewNo issues found. Checked for bugs and CLAUDE.md compliance. 🤖 Generated with Claude Code - If this code review was useful, please react with 👍. Otherwise, react with 👎. |
r-barnes
approved these changes
Mar 8, 2026
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Description
Raise the minimum C++ standard from C++17 to C++20 and adopt C++20 features throughout the extension codebase.
C++20 features adopted
std::format: Replace allstd::ostringstreamandoperator+string concatenation for error/exception messages withstd::format. Addstd::formatterspecializations forpy::handleandpy::object.std::source_location: Replace__FILE__,__LINE__, and__PRETTY_FUNCTION__macros inInternalErrorwithstd::source_location::current()default parameters.std::span: Replace raw pointer + size pairs (py::object *children, ssize_t num_children) withstd::span<py::object>inMakeNodeand related functions.std::ranges: Replacestd::copy/std::reversewith iterator pairs bystd::ranges::copy/std::ranges::reversewith range arguments.requiresclauses: Replacestd::enable_if_tSFINAE with C++20requiresexpressions in template functions (TupleGetItemAs,ListGetItemAs,DictGetItemAs).std::unordered_map::contains: Replace.find() != .end()pattern with.contains().Build and CI changes
CMakeLists.txt: Raise minimum standard from C++17 to C++20.MACOSX_DEPLOYMENT_TARGET=15.0andIPHONEOS_DEPLOYMENT_TARGET=16.3(required forstd::formatsupport in Apple libc++)..clang-formatstandard toc++20andclang-tidyto use C++20.Motivation and Context
C++20 provides standard library features that simplify the codebase and improve code clarity:
std::formateliminates verbosestd::ostringstreampatterns for string formatting.std::source_locationreplaces non-portable compiler macros (__PRETTY_FUNCTION__) with a standard mechanism.std::spanprovides a safer, more expressive alternative to raw pointer + size parameters.This is a breaking change: C++20 compiler support is now required to build the extension from source.
Types of changes
Checklist
make format. (required)make lint. (required)make testpass. (required)