[remote_base] Optimize raw transmit action memory usage - use function pointers

esphome/components/remote_base/raw_protocol.h

@@ -42,17 +42,21 @@ class RawTrigger : public Trigger<RawTimings>, public Component, public RemoteRe
 
 template<typename... Ts> class RawAction : public RemoteTransmitterActionBase<Ts...> {
  public:
-  void set_code_template(std::function<RawTimings(Ts...)> func) { this->code_func_ = func; }
+  void set_code_template(RawTimings (*func)(Ts...)) {
+    this->code_.func = func;
+    this->static_ = false;
+  }
   void set_code_static(const int32_t *code, size_t len) {
-    this->code_static_ = code;
-    this->code_static_len_ = len;
+    this->code_.static_code.data = code;
+    this->code_.static_code.len = len;
+    this->static_ = true;
   }
   TEMPLATABLE_VALUE(uint32_t, carrier_frequency);
 
   void encode(RemoteTransmitData *dst, Ts... x) override {
-    if (this->code_static_ != nullptr) {
-      for (size_t i = 0; i < this->code_static_len_; i++) {
-        auto val = this->code_static_[i];
+    if (this->static_) {
+      for (size_t i = 0; i < this->code_.static_code.len; i++) {
+        auto val = this->code_.static_code.data[i];
         if (val < 0) {
           dst->space(static_cast<uint32_t>(-val));
         } else {
@@ -60,15 +64,20 @@ template<typename... Ts> class RawAction : public RemoteTransmitterActionBase<Ts
         }
       }
     } else {
-      dst->set_data(this->code_func_(x...));
+      dst->set_data(this->code_.func(x...));
     }
     dst->set_carrier_frequency(this->carrier_frequency_.value(x...));
   }
 
  protected:
-  std::function<RawTimings(Ts...)> code_func_{nullptr};
-  const int32_t *code_static_{nullptr};
-  int32_t code_static_len_{0};
+  bool static_{true};
+  union Code {
+    RawTimings (*func)(Ts...);
+    struct {
+      const int32_t *data;
+      size_t len;
+    } static_code;
+  } code_;
 };
 
 class RawDumper : public RemoteReceiverDumperBase {

tests/components/remote_transmitter/common-buttons.yaml

@@ -1,3 +1,11 @@
+number:
+  - platform: template
+    id: test_number
+    optimistic: true
+    min_value: 0
+    max_value: 255
+    step: 1
+
 button:
   - platform: template
     name: Beo4 audio mute
@@ -128,10 +136,16 @@ button:
         address: 0x00
         command: 0x0B
   - platform: template
-    name: RC5 Raw
+    name: RC5 Raw static
     on_press:
       remote_transmitter.transmit_raw:
         code: [1000, -1000]
+  - platform: template
+    name: RC5 Raw lambda
+    on_press:
+      remote_transmitter.transmit_raw:
+        code: !lambda |-
+          return {(int32_t)id(test_number).state * 100, -1000};
   - platform: template
     name: AEHA
     id: eaha_hitachi_climate_power_on