module.hpp File Reference

Rod-agnostic module entry point — the WELDER_MODULE macro. More...

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Classes
struct	welder::detail::module_welder< Default, Override >
	Pick the entry macro's welder: the user's optional override, else the rod's default welder::welder<rod>. More...
struct	welder::detail::module_welder< Default, First, Rest... >

Namespaces
namespace	welder
namespace	welder::detail
	The stored forms of the annotation vocabulary.

Macros
#define	WELDER_MODULE(ns, rod, ...)
	Emit a binding module's entry point and weld a namespace into it.

Typedefs
template<class Default, class... Override>
using	welder::detail::module_welder_t = typename module_welder<Default, Override...>::type

Detailed Description

Rod-agnostic module entry point — the WELDER_MODULE macro.

Definition in file module.hpp.

Macro Definition Documentation

WELDER_MODULE

#define WELDER_MODULE	(		ns,
			rod,
			... )

Value:

WELDER_DETAIL_MODULE_ENTRY_##rod(ns __VA_OPT__(, ) __VA_ARGS__)

Emit a binding module's entry point and weld a namespace into it.

Parameters

ns	the namespace to bind; its token doubles as the module name.
rod	the rod selector (e.g. pybind11).
...	optionally, the exact welder::welder<…> type to drive the weld with — the way to thread a name style (or a custom carriage) through the one-line module form. Defaults to the rod's plain welder::welder<rod>. Commas inside the template-id are fine (the macro is variadic), and the type's module_type must match the selected rod's (checked by a static_assert in the expansion): WELDER_MODULE(geometry, pybind11, welder::welder<welder::rods::pybind11::rod<>, welder::rods::python::pep8>) {}

Defining a binding module needs exactly one irreducible macro. A target runtime imports a module by a pasted entry symbol — Python's PyInit_<name>, Lua's luaopen_<name> — and only the preprocessor can form that token; it cannot be synthesized from a reflection or a constexpr string. WELDER_MODULE hides which rod's macro forms it behind one uniform, rod-selected spelling, so the call site is the same across rods.

Because each language has its own entry symbol, a single shared object can expose several languages at once — one WELDER_MODULE per rod, each emitting its own symbol from the same namespace:

WELDER_MODULE(geometry, pybind11) { module.attr("VERSION") = "1.0"; }
WELDER_MODULE(geometry, sol2)     { module["VERSION"] = "1.0"; } // Lua glue

(pybind11 and nanobind both emit PyInit_<name>, so those two can't coexist in one module — pick one Python rod.)

The namespace token doubles as the module name: geometry is both ^^geometry (the bound namespace) and the PyInit_geometry / luaopen_geometry symbol, so there is no separate name argument. The trailing { } is optional hand-written glue, run after welder binds the namespace, with the rod's module handle named module in scope; write {} for none.

rod selects the expansion WELDER_DETAIL_MODULE_ENTRY_<rod>, which the corresponding rod's module.hpp defines (e.g. <welder/rods/python/pybind11/module.hpp>). Selecting a rod whose module.hpp you did not include is a preprocessor error.

Definition at line 78 of file module.hpp.