Avoid relying on compiler optimizations for binary conversions

* Add/update binary conversion functions to use `std::memcopy`
* Only GCC could actually optimize the custom code using bit operations
    * Clang could only optimize the `getBytes()` functions
    * MSVC could not optimize any of the functions
* The to…Int…() functions cannot be updated as they are `constexpr` (and
  thus `std::memcopy` and `reinterpret_cast` cannot be used). So they stay
  as-is and `toInt()` has been added instead
* The `BinaryReader` class has been updated to use the new `toInt()`
  function

conversion/binaryconversion.h

@@ -5,6 +5,7 @@
 #include "../misc/traits.h"
 
 #include <cstdint>
+#include <cstring>
 
 // use helpers from bits header if available instead of custom code using bit operations
 #if __cplusplus >= 202002L

conversion/binaryconversionprivate.h

@@ -133,31 +133,21 @@ CPP_UTILITIES_EXPORT inline double toFloat64(const char *value)
 }
 
 /*!
- * \brief Stores the specified 16-bit signed integer value at a specified position in a char array.
+ * \brief Returns the specified (unsigned) integer converted from the specified char array.
+ * \remarks
+ * - The \a value must point to a sequence of characters that is at least as long as the specified integer type.
+ * - This function is potentially faster than the width-specific toInt…() because the width-specific functions use
+ *   custom code that may not be optimized by the compiler. (Only GCC optimized it but not Clang and MSVC.) Note
+ *   that the width-specific functions cannot be changed as they are constexpr and thus cannot use memcpy().
  */
-CPP_UTILITIES_EXPORT inline void getBytes(std::int16_t value, char *outputbuffer)
+template <class T, Traits::EnableIf<std::is_integral<T>> * = nullptr> CPP_UTILITIES_EXPORT inline T toInt(const char *value)
 {
+    auto dst = T();
+    std::memcpy(&dst, value, sizeof(T));
 #if CONVERSION_UTILITIES_BINARY_CONVERSION_INTERNAL == 0
-    outputbuffer[0] = static_cast<char>((value >> 8) & 0xFF);
+    dst = swapOrder(dst);
-    outputbuffer[1] = static_cast<char>((value)&0xFF);
-#else
-    outputbuffer[1] = static_cast<char>((value >> 8) & 0xFF);
-    outputbuffer[0] = static_cast<char>((value)&0xFF);
-#endif
-}
-
-/*!
- * \brief Stores the specified 16-bit unsigned integer value at a specified position in a char array.
- */
-CPP_UTILITIES_EXPORT inline void getBytes(std::uint16_t value, char *outputbuffer)
-{
-#if CONVERSION_UTILITIES_BINARY_CONVERSION_INTERNAL == 0
-    outputbuffer[0] = static_cast<char>((value >> 8) & 0xFF);
-    outputbuffer[1] = static_cast<char>((value)&0xFF);
-#else
-    outputbuffer[1] = static_cast<char>((value >> 8) & 0xFF);
-    outputbuffer[0] = static_cast<char>((value)&0xFF);
 #endif
+    return dst;
 }
 
 /*!
@@ -178,91 +168,18 @@ CPP_UTILITIES_EXPORT inline void getBytes24(std::uint32_t value, char *outputbuf
 }
 
 /*!
- * \brief Stores the specified 32-bit signed integer value at a specified position in a char array.
+ * \brief Stores the specified (unsigned) integer value in a char array.
+ * \remarks
+ * - The \a value outputbuffer must point to a sequence of characters that is at least as long as the specified integer type.
+ * - This function is potentially faster than the width-specific toInt…() because the width-specific functions use
+ *   custom code that may not be optimized by the compiler. (Only GCC optimized it but not Clang and MSVC.)
  */
-CPP_UTILITIES_EXPORT inline void getBytes(std::int32_t value, char *outputbuffer)
+template <class T, Traits::EnableIf<std::is_integral<T>> * = nullptr> CPP_UTILITIES_EXPORT inline void getBytes(T value, char *outputbuffer)
 {
 #if CONVERSION_UTILITIES_BINARY_CONVERSION_INTERNAL == 0
-    outputbuffer[0] = static_cast<char>((value >> 24) & 0xFF);
+    value = swapOrder(value);
-    outputbuffer[1] = static_cast<char>((value >> 16) & 0xFF);
-    outputbuffer[2] = static_cast<char>((value >> 8) & 0xFF);
-    outputbuffer[3] = static_cast<char>((value)&0xFF);
-#else
-    outputbuffer[3] = static_cast<char>((value >> 24) & 0xFF);
-    outputbuffer[2] = static_cast<char>((value >> 16) & 0xFF);
-    outputbuffer[1] = static_cast<char>((value >> 8) & 0xFF);
-    outputbuffer[0] = static_cast<char>((value)&0xFF);
-#endif
-}
-
-/*!
- * \brief Stores the specified 32-bit signed integer value at a specified position in a char array.
- */
-CPP_UTILITIES_EXPORT inline void getBytes(std::uint32_t value, char *outputbuffer)
-{
-#if CONVERSION_UTILITIES_BINARY_CONVERSION_INTERNAL == 0
-    outputbuffer[0] = static_cast<char>((value >> 24) & 0xFF);
-    outputbuffer[1] = static_cast<char>((value >> 16) & 0xFF);
-    outputbuffer[2] = static_cast<char>((value >> 8) & 0xFF);
-    outputbuffer[3] = static_cast<char>((value)&0xFF);
-#else
-    outputbuffer[3] = static_cast<char>((value >> 24) & 0xFF);
-    outputbuffer[2] = static_cast<char>((value >> 16) & 0xFF);
-    outputbuffer[1] = static_cast<char>((value >> 8) & 0xFF);
-    outputbuffer[0] = static_cast<char>((value)&0xFF);
-#endif
-}
-
-/*!
- * \brief Stores the specified 64-bit signed integer value at a specified position in a char array.
- */
-CPP_UTILITIES_EXPORT inline void getBytes(std::int64_t value, char *outputbuffer)
-{
-#if CONVERSION_UTILITIES_BINARY_CONVERSION_INTERNAL == 0
-    outputbuffer[0] = static_cast<char>((value >> 56) & 0xFF);
-    outputbuffer[1] = static_cast<char>((value >> 48) & 0xFF);
-    outputbuffer[2] = static_cast<char>((value >> 40) & 0xFF);
-    outputbuffer[3] = static_cast<char>((value >> 32) & 0xFF);
-    outputbuffer[4] = static_cast<char>((value >> 24) & 0xFF);
-    outputbuffer[5] = static_cast<char>((value >> 16) & 0xFF);
-    outputbuffer[6] = static_cast<char>((value >> 8) & 0xFF);
-    outputbuffer[7] = static_cast<char>((value)&0xFF);
-#else
-    outputbuffer[7] = static_cast<char>((value >> 56) & 0xFF);
-    outputbuffer[6] = static_cast<char>((value >> 48) & 0xFF);
-    outputbuffer[5] = static_cast<char>((value >> 40) & 0xFF);
-    outputbuffer[4] = static_cast<char>((value >> 32) & 0xFF);
-    outputbuffer[3] = static_cast<char>((value >> 24) & 0xFF);
-    outputbuffer[2] = static_cast<char>((value >> 16) & 0xFF);
-    outputbuffer[1] = static_cast<char>((value >> 8) & 0xFF);
-    outputbuffer[0] = static_cast<char>((value)&0xFF);
-#endif
-}
-
-/*!
- * \brief Stores the specified 64-bit unsigned integer value at a specified position in a char array.
- */
-CPP_UTILITIES_EXPORT inline void getBytes(std::uint64_t value, char *outputbuffer)
-{
-#if CONVERSION_UTILITIES_BINARY_CONVERSION_INTERNAL == 0
-    outputbuffer[0] = static_cast<char>((value >> 56) & 0xFF);
-    outputbuffer[1] = static_cast<char>((value >> 48) & 0xFF);
-    outputbuffer[2] = static_cast<char>((value >> 40) & 0xFF);
-    outputbuffer[3] = static_cast<char>((value >> 32) & 0xFF);
-    outputbuffer[4] = static_cast<char>((value >> 24) & 0xFF);
-    outputbuffer[5] = static_cast<char>((value >> 16) & 0xFF);
-    outputbuffer[6] = static_cast<char>((value >> 8) & 0xFF);
-    outputbuffer[7] = static_cast<char>((value)&0xFF);
-#else
-    outputbuffer[7] = static_cast<char>((value >> 56) & 0xFF);
-    outputbuffer[6] = static_cast<char>((value >> 48) & 0xFF);
-    outputbuffer[5] = static_cast<char>((value >> 40) & 0xFF);
-    outputbuffer[4] = static_cast<char>((value >> 32) & 0xFF);
-    outputbuffer[3] = static_cast<char>((value >> 24) & 0xFF);
-    outputbuffer[2] = static_cast<char>((value >> 16) & 0xFF);
-    outputbuffer[1] = static_cast<char>((value >> 8) & 0xFF);
-    outputbuffer[0] = static_cast<char>((value)&0xFF);
 #endif
+    std::memcpy(outputbuffer, &value, sizeof(T));
 }
 
 /*!

io/binaryreader.h

@@ -243,7 +243,7 @@ inline void BinaryReader::read(std::vector<char> &buffer, std::streamsize length
 inline std::int16_t BinaryReader::readInt16BE()
 {
     m_stream->read(m_buffer, sizeof(std::int16_t));
-    return BE::toInt16(m_buffer);
+    return BE::toInt<std::int16_t>(m_buffer);
 }
 
 /*!
@@ -252,7 +252,7 @@ inline std::int16_t BinaryReader::readInt16BE()
 inline std::uint16_t BinaryReader::readUInt16BE()
 {
     m_stream->read(m_buffer, sizeof(std::uint16_t));
-    return BE::toUInt16(m_buffer);
+    return BE::toInt<std::uint16_t>(m_buffer);
 }
 
 /*!
@@ -262,7 +262,7 @@ inline std::int32_t BinaryReader::readInt24BE()
 {
     *m_buffer = 0;
     m_stream->read(m_buffer + 1, 3);
-    auto val = BE::toInt32(m_buffer);
+    auto val = BE::toInt<std::int32_t>(m_buffer);
     if (val >= 0x800000) {
         val = -(0x1000000 - val);
     }
@@ -276,7 +276,7 @@ inline std::uint32_t BinaryReader::readUInt24BE()
 {
     *m_buffer = 0;
     m_stream->read(m_buffer + 1, 3);
-    return BE::toUInt32(m_buffer);
+    return BE::toInt<std::uint32_t>(m_buffer);
 }
 
 /*!
@@ -285,7 +285,7 @@ inline std::uint32_t BinaryReader::readUInt24BE()
 inline std::int32_t BinaryReader::readInt32BE()
 {
     m_stream->read(m_buffer, sizeof(std::int32_t));
-    return BE::toInt32(m_buffer);
+    return BE::toInt<std::int32_t>(m_buffer);
 }
 
 /*!
@@ -294,7 +294,7 @@ inline std::int32_t BinaryReader::readInt32BE()
 inline std::uint32_t BinaryReader::readUInt32BE()
 {
     m_stream->read(m_buffer, sizeof(std::uint32_t));
-    return BE::toUInt32(m_buffer);
+    return BE::toInt<std::uint32_t>(m_buffer);
 }
 
 /*!
@@ -304,7 +304,7 @@ inline std::int64_t BinaryReader::readInt40BE()
 {
     *m_buffer = *(m_buffer + 1) = *(m_buffer + 2) = 0;
     m_stream->read(m_buffer + 3, 5);
-    auto val = BE::toInt64(m_buffer);
+    auto val = BE::toInt<std::int64_t>(m_buffer);
     if (val >= 0x8000000000) {
         val = -(0x10000000000 - val);
     }
@@ -318,7 +318,7 @@ inline std::uint64_t BinaryReader::readUInt40BE()
 {
     *m_buffer = *(m_buffer + 1) = *(m_buffer + 2) = 0;
     m_stream->read(m_buffer + 3, 5);
-    return BE::toUInt64(m_buffer);
+    return BE::toInt<std::uint64_t>(m_buffer);
 }
 
 /*!
@@ -328,7 +328,7 @@ inline std::int64_t BinaryReader::readInt56BE()
 {
     *m_buffer = 0;
     m_stream->read(m_buffer + 1, 7);
-    auto val = BE::toInt64(m_buffer);
+    auto val = BE::toInt<std::int64_t>(m_buffer);
     if (val >= 0x80000000000000) {
         val = -(0x100000000000000 - val);
     }
@@ -342,7 +342,7 @@ inline std::uint64_t BinaryReader::readUInt56BE()
 {
     *m_buffer = 0;
     m_stream->read(m_buffer + 1, 7);
-    return BE::toUInt64(m_buffer);
+    return BE::toInt<std::uint64_t>(m_buffer);
 }
 
 /*!
@@ -351,7 +351,7 @@ inline std::uint64_t BinaryReader::readUInt56BE()
 inline std::int64_t BinaryReader::readInt64BE()
 {
     m_stream->read(m_buffer, sizeof(std::int64_t));
-    return BE::toInt64(m_buffer);
+    return BE::toInt<std::int64_t>(m_buffer);
 }
 
 /*!
@@ -360,7 +360,7 @@ inline std::int64_t BinaryReader::readInt64BE()
 inline std::uint64_t BinaryReader::readUInt64BE()
 {
     m_stream->read(m_buffer, sizeof(std::uint64_t));
-    return BE::toUInt64(m_buffer);
+    return BE::toInt<std::uint64_t>(m_buffer);
 }
 
 /*!
@@ -370,7 +370,7 @@ inline std::uint64_t BinaryReader::readUInt64BE()
 inline std::uint64_t BinaryReader::readVariableLengthUIntBE()
 {
     bufferVariableLengthInteger();
-    return BE::toUInt64(m_buffer);
+    return BE::toInt<std::uint64_t>(m_buffer);
 }
 
 /*!
@@ -397,7 +397,7 @@ inline double BinaryReader::readFloat64BE()
 inline std::int16_t BinaryReader::readInt16LE()
 {
     m_stream->read(m_buffer, sizeof(std::int16_t));
-    return LE::toInt16(m_buffer);
+    return LE::toInt<std::int16_t>(m_buffer);
 }
 
 /*!
@@ -406,7 +406,7 @@ inline std::int16_t BinaryReader::readInt16LE()
 inline std::uint16_t BinaryReader::readUInt16LE()
 {
     m_stream->read(m_buffer, sizeof(std::uint16_t));
-    return LE::toUInt16(m_buffer);
+    return LE::toInt<std::uint16_t>(m_buffer);
 }
 
 /*!
@@ -416,7 +416,7 @@ inline std::int32_t BinaryReader::readInt24LE()
 {
     *(m_buffer + 3) = 0;
     m_stream->read(m_buffer, 3);
-    auto val = LE::toInt32(m_buffer);
+    auto val = LE::toInt<std::int32_t>(m_buffer);
     if (val >= 0x800000) {
         val = -(0x1000000 - val);
     }
@@ -430,7 +430,7 @@ inline std::uint32_t BinaryReader::readUInt24LE()
 {
     *(m_buffer + 3) = 0;
     m_stream->read(m_buffer, 3);
-    return LE::toUInt32(m_buffer);
+    return LE::toInt<std::uint32_t>(m_buffer);
 }
 
 /*!
@@ -439,7 +439,7 @@ inline std::uint32_t BinaryReader::readUInt24LE()
 inline std::int32_t BinaryReader::readInt32LE()
 {
     m_stream->read(m_buffer, sizeof(std::int32_t));
-    return LE::toInt32(m_buffer);
+    return LE::toInt<std::int32_t>(m_buffer);
 }
 
 /*!
@@ -448,7 +448,7 @@ inline std::int32_t BinaryReader::readInt32LE()
 inline std::uint32_t BinaryReader::readUInt32LE()
 {
     m_stream->read(m_buffer, sizeof(std::uint32_t));
-    return LE::toUInt32(m_buffer);
+    return LE::toInt<std::uint32_t>(m_buffer);
 }
 
 /*!
@@ -458,7 +458,7 @@ inline std::int64_t BinaryReader::readInt40LE()
 {
     *(m_buffer + 5) = *(m_buffer + 6) = *(m_buffer + 7) = 0;
     m_stream->read(m_buffer, 5);
-    auto val = LE::toInt64(m_buffer);
+    auto val = LE::toInt<std::int64_t>(m_buffer);
     if (val >= 0x8000000000) {
         val = -(0x10000000000 - val);
     }
@@ -472,7 +472,7 @@ inline std::uint64_t BinaryReader::readUInt40LE()
 {
     *(m_buffer + 5) = *(m_buffer + 6) = *(m_buffer + 7) = 0;
     m_stream->read(m_buffer, 5);
-    return LE::toUInt64(m_buffer);
+    return LE::toInt<std::uint64_t>(m_buffer);
 }
 
 /*!
@@ -482,7 +482,7 @@ inline std::int64_t BinaryReader::readInt56LE()
 {
     *(m_buffer + 7) = 0;
     m_stream->read(m_buffer, 7);
-    auto val = LE::toInt64(m_buffer);
+    auto val = LE::toInt<std::int64_t>(m_buffer);
     if (val >= 0x80000000000000) {
         val = -(0x100000000000000 - val);
     }
@@ -496,7 +496,7 @@ inline std::uint64_t BinaryReader::readUInt56LE()
 {
     *(m_buffer + 7) = 0;
     m_stream->read(m_buffer, 7);
-    return LE::toUInt64(m_buffer);
+    return LE::toInt<std::uint64_t>(m_buffer);
 }
 
 /*!
@@ -505,7 +505,7 @@ inline std::uint64_t BinaryReader::readUInt56LE()
 inline std::int64_t BinaryReader::readInt64LE()
 {
     m_stream->read(m_buffer, sizeof(std::int64_t));
-    return LE::toInt64(m_buffer);
+    return LE::toInt<std::int64_t>(m_buffer);
 }
 
 /*!
@@ -514,7 +514,7 @@ inline std::int64_t BinaryReader::readInt64LE()
 inline std::uint64_t BinaryReader::readUInt64LE()
 {
     m_stream->read(m_buffer, sizeof(std::uint64_t));
-    return LE::toUInt64(m_buffer);
+    return LE::toInt<std::uint64_t>(m_buffer);
 }
 
 /*!
@@ -524,7 +524,7 @@ inline std::uint64_t BinaryReader::readUInt64LE()
 inline std::uint64_t BinaryReader::readVariableLengthUIntLE()
 {
     bufferVariableLengthInteger();
-    return LE::toUInt64(m_buffer);
+    return LE::toInt<std::uint64_t>(m_buffer);
 }
 
 /*!