replace reinterpret_cast with memcpy

Avoids potential aliasing issues.

Signed-off-by: Rosen Penev <[email protected]>

Author: neheb

src/bmffimage.cpp

@@ -20,6 +20,7 @@
 #endif
 
 // + standard includes
+#include <array>
 #include <cstdio>
 #include <cstring>
 #include <iostream>
@@ -86,8 +87,9 @@ BmffImage::BmffImage(BasicIo::UniquePtr io, bool /* create */, size_t max_box_de
 }  // BmffImage::BmffImage
 
 std::string BmffImage::toAscii(uint32_t n) {
-  const auto p = reinterpret_cast<const char*>(&n);
-  std::string result(p, p + 4);
+  std::array<char, sizeof(uint32_t)> p;
+  std::memcpy(p.data(), &n, sizeof(uint32_t));
+  std::string result(p.begin(), p.end());
   if (!isBigEndianPlatform())
     std::reverse(result.begin(), result.end());
   // show 0 as _

src/jp2image.cpp

@@ -112,8 +112,9 @@ Jp2Image::Jp2Image(BasicIo::UniquePtr io, bool create) : Image(ImageType::jp2, m
 
 // Obtains the ascii version from the box.type
 std::string Jp2Image::toAscii(uint32_t n) {
-  const auto p = reinterpret_cast<const char*>(&n);
-  std::string result(p, p + 4);
+  std::array<char, sizeof(uint32_t)> p;
+  std::memcpy(p.data(), &n, sizeof(uint32_t));
+  std::string result(p.begin(), p.end());
   if (isBigEndianPlatform())
     return result;
   std::reverse(result.begin(), result.end());