Use constexpr where possible for method return values

mikee47 · Apr 7, 2024 · 3ee3da9 · 3ee3da9
1 parent cdff515
commit 3ee3da9
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Showing 4 changed files with 17 additions and 18 deletions.
diff --git a/src/ObjectBase.cpp b/src/ObjectBase.cpp
@@ -60,17 +60,6 @@ size_t ObjectBase::read(size_t offset, void* buffer, size_t count) const
 	return count;
 }
 
-size_t ObjectBase::length() const
-{
-	if(isNull()) {
-		return 0;
-	} else if(isCopy()) {
-		return reinterpret_cast<const ObjectBase*>(flashLength_ & ~copyBit)->length();
-	} else {
-		return flashLength_;
-	}
-}
-
 const uint8_t* ObjectBase::data() const
 {
 	if(isNull()) {

diff --git a/src/include/FlashString/Object.hpp b/src/include/FlashString/Object.hpp
@@ -157,15 +157,15 @@ template <class ObjectType, typename ElementType> class Object : public ObjectBa
 	/**
 	 * @brief Return an empty object which evaluates to null
 	 */
-	static const ObjectType& empty()
+	static constexpr const ObjectType& empty()
 	{
-		return empty_.as<ObjectType>();
+		return empty_.as<const ObjectType>();
 	}
 
 	/**
 	 * @brief Get the length of the content in elements
 	 */
-	FSTR_INLINE size_t length() const
+	FSTR_INLINE constexpr const size_t length() const
 	{
 		return ObjectBase::length() / sizeof(ElementType);
 	}

diff --git a/src/include/FlashString/ObjectBase.hpp b/src/include/FlashString/ObjectBase.hpp
@@ -35,13 +35,22 @@ class ObjectBase
 	/**
 	 * @brief Get the length of the object data in bytes
 	 */
-	size_t length() const;
+	FSTR_NOINLINE constexpr const size_t length() const
+	{
+		if(isNull()) {
+			return 0;
+		}
+		if(isCopy()) {
+			return reinterpret_cast<const ObjectBase*>(flashLength_ & ~copyBit)->length();
+		}
+		return flashLength_;
+	}
 
 	/**
 	 * @brief Get the object data size in bytes
 	 * @note Always an integer multiple of 4 bytes
 	 */
-	FSTR_INLINE size_t size() const
+	FSTR_INLINE constexpr const size_t size() const
 	{
 		return ALIGNUP4(length());
 	}
@@ -89,7 +98,7 @@ class ObjectBase
 	 */
 	size_t readFlash(size_t offset, void* buffer, size_t count) const;
 
-	FSTR_INLINE bool isCopy() const
+	FSTR_INLINE constexpr const bool isCopy() const
 	{
 		return (flashLength_ & copyBit) != 0;
 	}
@@ -98,7 +107,7 @@ class ObjectBase
 	 * @brief Indicates an invalid String, used for return value from lookups, etc.
 	 * @note A real String can be zero-length, but it cannot be null
 	 */
-	FSTR_INLINE bool isNull() const
+	FSTR_INLINE constexpr const bool isNull() const
 	{
 		return flashLength_ == lengthInvalid;
 	}

diff --git a/src/include/FlashString/config.hpp b/src/include/FlashString/config.hpp
@@ -26,6 +26,7 @@
 #include <stringutil.h>
 
 #define FSTR_INLINE __attribute__((always_inline)) inline
+#define FSTR_NOINLINE __attribute__((noinline))
 #define FSTR_ALIGNED __attribute__((aligned(4)))
 #define FSTR_PACKED __attribute__((packed))