Use bit_cast instead of pointer bullshit that breaks strict aliasing

Author: sorsarre

bitreader/include/bitreader/bitreader.hpp

@@ -85,10 +85,9 @@ namespace brcpp {
         {
             using FT = fitting_integral<T>;
             _validate_read_dynamic<T>(bits);
-            T ret = zero<T>;
-            auto& raw = reinterpret_cast<FT&>(ret);
+            auto raw = zero<FT>;
             _read(_state, bits, raw);
-            return _sign_extend(ret, bits);
+            return _sign_extend(std::bit_cast<T>(raw), bits);
         }
 
         template<binary_codec T>

bitreader/include/bitreader/bitwriter.hpp

@@ -59,7 +59,7 @@ namespace brcpp {
             size_t to_write = bits;
 
             using FT = fitting_integral<T>;
-            const auto bit_data = *reinterpret_cast<const FT*>(&data);
+            const auto bit_data = std::bit_cast<FT>(data);
 
             while (written < bits) {
                 size_t post = std::min<uint64_t>(_state.avail, to_write);

bitreader/test/bitreader_gtest.cpp

@@ -425,7 +425,7 @@ TEST(bitreaderTest, read_float_aligned)
     bitreader<source_t> br(source);
 
     const uint32_t raw_expected = 0x4148F5C3;
-    const auto expected = *reinterpret_cast<const float*>(&raw_expected);
+    const auto expected = std::bit_cast<float>(raw_expected);
     EXPECT_EQ(expected, br.read<float>(32));
     EXPECT_EQ(32, br.position());
     EXPECT_EQ(0, br.available());
@@ -439,7 +439,7 @@ TEST(bitreaderTest, read_double_aligned)
     bitreader<source_t> br(source);
 
     const uint64_t raw_expected = 0x4005BF0A8B145762;
-    const auto expected = *reinterpret_cast<const double*>(&raw_expected);
+    const auto expected = std::bit_cast<double>(raw_expected);
     EXPECT_EQ(expected, br.read<double>(64));
     EXPECT_EQ(64, br.position());
     EXPECT_EQ(0, br.available());
@@ -455,7 +455,7 @@ TEST(bitreaderTest, read_float_unaligned)
     br.skip(4);
 
     const uint32_t raw_expected = 0x02030405;
-    const auto expected = *reinterpret_cast<const float*>(&raw_expected);
+    const auto expected = std::bit_cast<float>(raw_expected);
     EXPECT_EQ(expected, br.read<float>(32)); // exact eq
     EXPECT_EQ(36, br.position());
     EXPECT_EQ(4, br.available());
@@ -471,7 +471,7 @@ TEST(bitreaderTest, read_double_unaligned)
     br.skip(4);
 
     const uint64_t raw_expected = 0x0203'0405'0607'0809;
-    const auto expected = *reinterpret_cast<const double*>(&raw_expected);
+    const auto expected = std::bit_cast<double>(raw_expected);
     EXPECT_EQ(expected, br.read<double>(64));
     EXPECT_EQ(68, br.position());
     EXPECT_EQ(4, br.available());