From 34b38e07c7836273e3730a9338bc4848ca9894a4 Mon Sep 17 00:00:00 2001
From: Benoit Blanchon <git@benoitblanchon.fr>
Date: Thu, 26 Jan 2023 18:10:41 +0100
Subject: [PATCH] Deduce template argument of `pgm_read()`

---
 .../Deserialization/DeserializationError.hpp   |  3 ++-
 src/ArduinoJson/Numbers/FloatTraits.hpp        | 18 +++++++++---------
 src/ArduinoJson/Polyfills/pgmspace_generic.hpp | 12 +++++-------
 3 files changed, 16 insertions(+), 17 deletions(-)

diff --git a/src/ArduinoJson/Deserialization/DeserializationError.hpp b/src/ArduinoJson/Deserialization/DeserializationError.hpp
index 9720096f..16c52ffd 100644
--- a/src/ArduinoJson/Deserialization/DeserializationError.hpp
+++ b/src/ArduinoJson/Deserialization/DeserializationError.hpp
@@ -82,7 +82,8 @@ class DeserializationError : public SafeBoolIdom<DeserializationError> {
     ARDUINOJSON_DEFINE_PROGMEM_ARRAY(char, s5, "TooDeep");
     ARDUINOJSON_DEFINE_PROGMEM_ARRAY(
         const char*, messages, ARDUINOJSON_EXPAND6({s0, s1, s2, s3, s4, s5}));
-    return pgm_read<const __FlashStringHelper*>(messages + _code);
+    return reinterpret_cast<const __FlashStringHelper*>(
+        pgm_read(messages + _code));
   }
 #endif
 
diff --git a/src/ArduinoJson/Numbers/FloatTraits.hpp b/src/ArduinoJson/Numbers/FloatTraits.hpp
index be15108d..08aa3d66 100644
--- a/src/ArduinoJson/Numbers/FloatTraits.hpp
+++ b/src/ArduinoJson/Numbers/FloatTraits.hpp
@@ -62,8 +62,8 @@ struct FloatTraits<T, 8 /*64bits*/> {
             0x5A827748, 0xF9301D32,  // 1e128
             0x75154FDD, 0x7F73BF3C   // 1e256
         }));
-    return forge(pgm_read<uint32_t>(factors + 2 * index),
-                 pgm_read<uint32_t>(factors + 2 * index + 1));
+    return forge(pgm_read(factors + 2 * index),
+                 pgm_read(factors + 2 * index + 1));
   }
 
   static T negativeBinaryPowerOfTen(int index) {
@@ -80,8 +80,8 @@ struct FloatTraits<T, 8 /*64bits*/> {
             0x255BBA08, 0xCF8C979D,  // 1e-128
             0x0AC80628, 0x64AC6F43   // 1e-256
         }));
-    return forge(pgm_read<uint32_t>(factors + 2 * index),
-                 pgm_read<uint32_t>(factors + 2 * index + 1));
+    return forge(pgm_read(factors + 2 * index),
+                 pgm_read(factors + 2 * index + 1));
   }
 
   static T negativeBinaryPowerOfTenPlusOne(int index) {
@@ -98,8 +98,8 @@ struct FloatTraits<T, 8 /*64bits*/> {
             0x25915445, 0x81B7DEC2,  // 1e-127
             0x0AFE07B2, 0x7DD78B14   // 1e-255
         }));
-    return forge(pgm_read<uint32_t>(factors + 2 * index),
-                 pgm_read<uint32_t>(factors + 2 * index + 1));
+    return forge(pgm_read(factors + 2 * index),
+                 pgm_read(factors + 2 * index + 1));
   }
 
   static T nan() {
@@ -181,7 +181,7 @@ struct FloatTraits<T, 4 /*32bits*/> {
                                          0x5a0e1bca,  // 1e16f
                                          0x749dc5ae   // 1e32f
                                      }));
-    return forge(pgm_read<uint32_t>(factors + index));
+    return forge(pgm_read(factors + index));
   }
 
   static T negativeBinaryPowerOfTen(int index) {
@@ -194,7 +194,7 @@ struct FloatTraits<T, 4 /*32bits*/> {
                                          0x24e69595,  // 1e-16f
                                          0x0a4fb11f   // 1e-32f
                                      }));
-    return forge(pgm_read<uint32_t>(factors + index));
+    return forge(pgm_read(factors + index));
   }
 
   static T negativeBinaryPowerOfTenPlusOne(int index) {
@@ -207,7 +207,7 @@ struct FloatTraits<T, 4 /*32bits*/> {
                                          0x26901d7d,  // 1e-15f
                                          0x0c01ceb3   // 1e-31f
                                      }));
-    return forge(pgm_read<uint32_t>(factors + index));
+    return forge(pgm_read(factors + index));
   }
 
   static T forge(uint32_t bits) {
diff --git a/src/ArduinoJson/Polyfills/pgmspace_generic.hpp b/src/ArduinoJson/Polyfills/pgmspace_generic.hpp
index 826827fb..106e0145 100644
--- a/src/ArduinoJson/Polyfills/pgmspace_generic.hpp
+++ b/src/ArduinoJson/Polyfills/pgmspace_generic.hpp
@@ -21,13 +21,11 @@ namespace ARDUINOJSON_NAMESPACE {
 #  endif
 
 template <typename T>
-typename enable_if<is_pointer<T>::value, T>::type pgm_read(const void* p) {
-  return reinterpret_cast<T>(pgm_read_ptr(p));
+inline const T* pgm_read(const T* const* p) {
+  return reinterpret_cast<const T*>(pgm_read_ptr(p));
 }
 
-template <typename T>
-typename enable_if<is_same<T, uint32_t>::value, T>::type pgm_read(
-    const void* p) {
+inline uint32_t pgm_read(const uint32_t* p) {
   return pgm_read_dword(p);
 }
 #else
@@ -38,8 +36,8 @@ typename enable_if<is_same<T, uint32_t>::value, T>::type pgm_read(
 #  endif
 
 template <typename T>
-inline T pgm_read(const void* p) {
-  return *reinterpret_cast<const T*>(p);
+inline T pgm_read(const T* p) {
+  return *p;
 }
 
 #endif