esphome::TemplateLambda< T, Args > Class Template Reference

Lightweight wrapper for template platform lambdas (stateless function pointers only). More...

#include <template_lambda.h>

Public Member Functions
	TemplateLambda ()
void	set (optional< T >(*f)(Args...))
	Set the lambda function pointer.
bool	has_value () const
	Check if a lambda is set.
optional< T >	operator() (Args &&...args)
	Call the lambda, returning nullopt if no lambda is set.
optional< T >	call (Args &&...args)
	Alias for operator() for compatibility.

Protected Attributes
optional< T >(*	f_ )(Args...)

Detailed Description

template<typename T, typename... Args>
class esphome::TemplateLambda< T, Args >

Lightweight wrapper for template platform lambdas (stateless function pointers only).

This optimizes template platforms by storing only a function pointer (4 bytes on ESP32) instead of std::function (16-32 bytes).

IMPORTANT: This only supports stateless lambdas (no captures). The set_template() method is an internal API used by YAML codegen, not intended for external use.

Lambdas must return optional<T> to support the pattern: return {}; // Don't publish a value return 42.0; // Publish this value

operator() returns optional<T>, returning nullopt when no lambda is set (nullptr check).

Template Parameters

T	The return type (e.g., float for sensor values)
Args	Optional arguments for the lambda

Definition at line 24 of file template_lambda.h.

Constructor & Destructor Documentation

TemplateLambda()

template<typename T , typename... Args>

esphome::TemplateLambda< T, Args >::TemplateLambda ( )

inline

Definition at line 26 of file template_lambda.h.

Member Function Documentation

call()

template<typename T , typename... Args>

optional< T > esphome::TemplateLambda< T, Args >::call ( Args &&... args )

inline

Alias for operator() for compatibility.

Definition at line 45 of file template_lambda.h.

has_value()

template<typename T , typename... Args>

bool esphome::TemplateLambda< T, Args >::has_value ( ) const

inline

Check if a lambda is set.

Definition at line 35 of file template_lambda.h.

operator()()

template<typename T , typename... Args>

optional< T > esphome::TemplateLambda< T, Args >::operator() ( Args &&... args )

inline

Call the lambda, returning nullopt if no lambda is set.

Definition at line 38 of file template_lambda.h.

set()

template<typename T , typename... Args>

void esphome::TemplateLambda< T, Args >::set ( optional< T >(* f )(Args...) )

inline

Set the lambda function pointer.

INTERNAL API: Only for use by YAML codegen. Only stateless lambdas (no captures) are supported.

Definition at line 32 of file template_lambda.h.

Field Documentation

f_

template<typename T , typename... Args>

optional< T >(* esphome::TemplateLambda< T, Args >::f_) (Args...)

protected

Definition at line 45 of file template_lambda.h.

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The documentation for this class was generated from the following file:

• esphome/core/template_lambda.h