Cookbook

Small, complete, runnable recipes — one per page, each a standalone consumer project under examples/cookbook/ and asserted by a CTest in CI. Where the guide explains each feature in isolation, a recipe shows the whole dish: the annotated C++, the CMake that builds it, and a check script that loads the module and proves what bound.

• 01 — One of everything — weld a type, an enum, a free function and a namespace variable, one weld_* call each.
• 02 — Discovery rules — policies, marks, nested namespaces, pruning detail, weld_as renames, WELDER_MODULE.
• 03 — Inheritance — welded bases become native bases; unwelded bases flatten in as mixins.
• 04 — Virtual methods — Python subclasses overriding C++ virtuals through hand-written trampolines.
• 05 — Generated trampolines — the same, with the trampolines reflection-generated at build time.
• 06 — Templates — weld class/function template instantiations under explicit names.
• 07 — One library, two languages — Python (nanobind) + Lua (sol2 and LuaBridge3) from one header: name styles, per-language weld_as, mark::only language flavors, .pyi + LuaCATS stubs.
• 08 — Tack welding — greedily bind a third-party library that carries no welder annotations at all.
• 09 — Custom traversal — subclass the tack resolution to honor a library's privacy convention: prune detail namespaces and _underscore internals.

Building the recipes

The cookbook is a standalone super-project: it obtains welder with FetchContent — exactly the way a consumer would — and FetchContent-pins the backends (pybind11, nanobind, sol2). No Conan, nothing preinstalled beyond gcc-16, CMake + Ninja, a Python, and (for the Lua half of recipe 07) a Lua install:

cmake -S examples/cookbook -B build/cookbook -G Ninja \
  -DCMAKE_CXX_COMPILER=g++-16 \
  -DWELDER_LUA_DIR="$(brew --prefix lua@5.4)"   # optional: enables the Lua recipe
cmake --build build/cookbook
ctest --test-dir build/cookbook --output-on-failure

By default welder itself is fetched from GitHub. welder's CI instead points the fetch at the current checkout (-DFETCHCONTENT_SOURCE_DIR_WELDER=$PWD), so every recipe — and the FetchContent consumption path itself — is exercised on every commit.

Copying a recipe

Each recipe directory is deliberately self-contained (one CMakeLists.txt, one or a few .cpp, a check script). To start your own project from one, copy the recipe directory plus the dependency block of the top-level CMakeLists.txt — that block is the "consume welder without Conan" reference.