[wdconinc]

Briefly, what does this PR introduce?

Closes #24. Generates algorithms/version.h from version_number at configure time and installs it alongside the other headers, so downstream code can depend on the algorithms version.

• Preprocessor macros for conditional compilation: ALGORITHMS_VERSION_MAJOR, _MINOR, _PATCH, ALGORITHMS_VERSION_STRING, ALGORITHMS_VERSION, and ALGORITHMS_VERSION_CODE(major, minor, patch), e.g.

  #if ALGORITHMS_VERSION >= ALGORITHMS_VERSION_CODE(2, 1, 0)

• constexpr values in namespace algorithms: versionMajor, versionMinor, versionPatch, versionString, and versionAtLeast(major, minor = 0, patch = 0).

ALGORITHMS_VERSION_CODE encodes major × 10⁶ + minor × 10³ + patch, so it orders correctly while minor and patch stay below 1000.

The template lives at core/version.h.in (outside include/, so the directory install doesn't pick it up); the generated header goes to the build tree, which is added to the build-interface include path.

What kind of change does this PR introduce?

• Bug fix
• New feature
• Documentation update
• Other

Testing

• New core/tests/version.cpp: macros and constants agree, version codes are ordered, versionAtLeast boundaries, and the macros are usable in #if.
• Locally in eic_xl-nightly with clang++ Debug (-Werror): all 98 tests pass, and cmake --install places include/algorithms/version.h. A downstream-style file including only the installed header compiles with g++ -std=c++17 -Wall -Wextra -Wpedantic -Werror.

🤖 Generated with Claude Code

[Copilot]

🟢 Approval recommended

The review surfaced no outstanding issues or comments requiring changes, leaving nothing to block approval.

No open issues 🎉

What changed in this PR

This PR resolves issue #24 by generating and installing a public algorithms/version.h header so downstream code can depend on the algorithms library version. The header is produced at configure time from the existing version_number source of truth (via configure_file) into the build tree, exposed on the build-interface include path, and installed alongside the other algorithms/ headers. It provides both preprocessor macros (for #if conditional compilation) and constexpr values/versionAtLeast(...) in namespace algorithms.

Changes:

• Added core/version.h.in template defining ALGORITHMS_VERSION_* macros, ALGORITHMS_VERSION_CODE(...), and constexpr versionMajor/Minor/Patch/String plus versionAtLeast(...).
• Wired configure_file, the build-interface include dir, and an install(FILES ...) rule into core/CMakeLists.txt; documented the header in README.md.
• Added core/tests/version.cpp (auto-registered via the test GLOB) covering macro/constant agreement, version-code ordering, versionAtLeast boundaries, and #if usability.

File	Description
core/​version.h.in	New template for the generated version header; macros + constexpr values and versionAtLeast with correct lexicographic comparison.
core/​CMakeLists.txt	Generates the header into the build tree, adds it to the build-interface include path, and installs it to include/algorithms.
core/​tests/​version.cpp	Catch2 tests validating macro/constant consistency, version-code ordering, and versionAtLeast boundaries.
README.md	Documents the new algorithms/version.h header in the feature list.

I reviewed the version-encoding math (major×10⁶ + minor×10³ + patch, documented to require minor/patch < 1000), the versionAtLeast logic (verified correct for all test cases against the current 2.1.0), the CMake configure/install wiring (build-tree generation avoids the source-dir install(DIRECTORY ...) and does not double-install), and convention consistency (#pragma once, SPDX header, STATIC_CHECK/fmt usage, auto test registration). The changes are self-contained, well-tested, and -Werror/C++17/C++20 clean. I found no issues requiring a comment.

_{Review effort: Balanced}