diff --git a/esphome/components/light/automation.h b/esphome/components/light/automation.h index 89328221335..c3451332649 100644 --- a/esphome/components/light/automation.h +++ b/esphome/components/light/automation.h @@ -37,14 +37,13 @@ template class ToggleAction : public A // Trigger args are forwarded to the apply function so user lambdas // (e.g. `brightness: !lambda "return x;"`) keep working. // -// Trigger args are forwarded as `Ts...`. The previous `const Ts &...` -// form caused codegen to emit `const T &` for each arg in the apply -// lambda's parameter list, which is invalid C++ source text when T is -// already a reference (e.g. `const std::string & &` for triggers that -// pass `std::string &`). +// Trigger args are forwarded as `const std::remove_reference_t &...` +// (instead of `const Ts &...`) so codegen can emit the same form in the +// apply lambda's parameter list without producing `const T & &` for +// triggers whose Ts already carries a reference (e.g. `std::string &`). template class LightControlAction : public Action { public: - using ApplyFn = void (*)(LightState *, LightCall &, Ts...); + using ApplyFn = void (*)(LightState *, LightCall &, const std::remove_reference_t &...); LightControlAction(LightState *parent, ApplyFn apply) : parent_(parent), apply_(apply) {} void play(const Ts &...x) override { diff --git a/esphome/components/light/automation.py b/esphome/components/light/automation.py index fd75e976ec0..3a086c68c38 100644 --- a/esphome/components/light/automation.py +++ b/esphome/components/light/automation.py @@ -230,15 +230,16 @@ async def light_control_to_code(config, action_id, template_arg, args): f"call.set_effect(static_cast({_resolve_effect_index(config)}));" ) - # Forward trigger args as Ts... so each (type, name) pair passes through - # unchanged. Wrapping in `const &` here would emit invalid C++ source - # for trigger types that already carry a reference (e.g. `std::string &`) - # and fails on plain Python types (`float`/`bool`) which have no - # `.operator()` method. + # Match LightControlAction::ApplyFn signature: `const std::remove_reference_t &` + # for each trigger arg so non-reference Ts stay no-copy (`const T &`) and + # reference Ts collapse correctly without producing `const T & &`. apply_args = [ (LightState.operator("ptr"), "parent"), (LightCall.operator("ref"), "call"), - *args, + *( + (cg.RawExpression(f"const std::remove_reference_t<{cg.safe_exp(t)}> &"), n) + for t, n in args + ), ] apply_lambda = LambdaExpression( ["\n".join(body_lines)],