From dd495be86146c0e04b92169ed63ea99378e40851 Mon Sep 17 00:00:00 2001
From: "J. Nick Koston" <nick@home-assistant.io>
Date: Mon, 12 Oct 2026 16:28:37 -1000
Subject: [PATCH] Fold dev's ProgmemStringRef struct into the class

---
 esphome/core/string_ref.h | 29 ++++++++++-------------------
 1 file changed, 10 insertions(+), 19 deletions(-)

diff --git a/esphome/core/string_ref.h b/esphome/core/string_ref.h
index 4e388a4d09..d8c68d7e7f 100644
--- a/esphome/core/string_ref.h
+++ b/esphome/core/string_ref.h
@@ -190,24 +190,6 @@ inline bool operator!=(const StringRef &lhs, const __FlashStringHelper *rhs) { r
 
 inline bool operator!=(const __FlashStringHelper *lhs, const StringRef &rhs) { return !(rhs == lhs); }
 
-/// Codegen use only: a flash string literal with its byte length, compared without a runtime strlen.
-struct ProgmemStringRef {
-  PGM_P str;
-  size_t len;
-};
-
-inline bool operator==(const std::string &lhs, ProgmemStringRef rhs) {
-  return lhs.size() == rhs.len && (rhs.len == 0 || memcmp_P(lhs.data(), rhs.str, rhs.len) == 0);
-}
-
-inline bool operator!=(const std::string &lhs, ProgmemStringRef rhs) { return !(lhs == rhs); }
-
-inline bool operator==(const StringRef &lhs, ProgmemStringRef rhs) {
-  // A StringRef may be {nullptr, 0}, and memcmp_P with a null pointer is undefined even for 0 bytes
-  return lhs.size() == rhs.len && (rhs.len == 0 || memcmp_P(lhs.c_str(), rhs.str, rhs.len) == 0);
-}
-
-inline bool operator!=(const StringRef &lhs, ProgmemStringRef rhs) { return !(lhs == rhs); }
 #endif  // USE_ESP8266
 
 inline bool operator<(const StringRef &lhs, const StringRef &rhs) {
@@ -271,7 +253,9 @@ class ProgmemStringRef {
 
   bool equals(const StringRef &other) const {
 #ifdef USE_ESP8266
-    return other.size() == this->ref_.size() && memcmp_P(other.c_str(), this->ref_.c_str(), other.size()) == 0;
+    // A StringRef may be {nullptr, 0}, and memcmp_P with a null pointer is undefined even for 0 bytes
+    return other.size() == this->ref_.size() &&
+           (other.empty() || memcmp_P(other.c_str(), this->ref_.c_str(), other.size()) == 0);
 #else
     return other == this->ref_;
 #endif
@@ -293,6 +277,13 @@ class ProgmemStringRef {
   StringRef ref_;
 };
 
+#ifdef USE_ESP8266
+inline bool operator==(const StringRef &lhs, const ProgmemStringRef &rhs) { return rhs.equals(lhs); }
+inline bool operator!=(const StringRef &lhs, const ProgmemStringRef &rhs) { return !rhs.equals(lhs); }
+inline bool operator==(const std::string &lhs, const ProgmemStringRef &rhs) { return rhs.equals(StringRef(lhs)); }
+inline bool operator!=(const std::string &lhs, const ProgmemStringRef &rhs) { return !rhs.equals(StringRef(lhs)); }
+#endif
+
 // String conversion functions for ADL compatibility (allows stoi(x) where x is StringRef)
 // Must be in esphome namespace for ADL to find them. Uses strtol/strtod directly to avoid heap allocation.
 namespace internal {