Merge #16730: Support serialization of std::vector<bool>

92528c2 Support serialization of std::vector<bool> (Pieter Wuille)

Pull request description:

  This adds support for serialization of `std::vector<bool>`, as a prerequisite of #16702.

ACKs for top commit:
  MarcoFalke:
    ACK 92528c2 (only looked at the diff on GitHub)
  practicalswift:
    ACK 92528c2 -- diff looks correct
  jamesob:
    ACK bitcoin/bitcoin@92528c2

Tree-SHA512: 068246a55a889137098f817bf72d99fc3218a560d62a97c59cccc0392b110f6778843cee4e89d56f271ac64e03a0f64dc5e2cc22daa833fbbbe9234c5f42d7b9

Author: fanquake

src/serialize.h

@@ -555,6 +555,7 @@ template<typename Stream, unsigned int N, typename T> inline void Unserialize(St
  * vectors of unsigned char are a special case and are intended to be serialized as a single opaque blob.
  */
 template<typename Stream, typename T, typename A> void Serialize_impl(Stream& os, const std::vector<T, A>& v, const unsigned char&);
+template<typename Stream, typename T, typename A> void Serialize_impl(Stream& os, const std::vector<T, A>& v, const bool&);
 template<typename Stream, typename T, typename A, typename V> void Serialize_impl(Stream& os, const std::vector<T, A>& v, const V&);
 template<typename Stream, typename T, typename A> inline void Serialize(Stream& os, const std::vector<T, A>& v);
 template<typename Stream, typename T, typename A> void Unserialize_impl(Stream& is, std::vector<T, A>& v, const unsigned char&);
@@ -713,6 +714,18 @@ void Serialize_impl(Stream& os, const std::vector<T, A>& v, const unsigned char&
         os.write((char*)v.data(), v.size() * sizeof(T));
 }
 
+template<typename Stream, typename T, typename A>
+void Serialize_impl(Stream& os, const std::vector<T, A>& v, const bool&)
+{
+    // A special case for std::vector<bool>, as dereferencing
+    // std::vector<bool>::const_iterator does not result in a const bool&
+    // due to std::vector's special casing for bool arguments.
+    WriteCompactSize(os, v.size());
+    for (bool elem : v) {
+        ::Serialize(os, elem);
+    }
+}
+
 template<typename Stream, typename T, typename A, typename V>
 void Serialize_impl(Stream& os, const std::vector<T, A>& v, const V&)
 {

src/test/serialize_tests.cpp

@@ -258,6 +258,14 @@ static bool isCanonicalException(const std::ios_base::failure& ex)
     return strcmp(expectedException.what(), ex.what()) == 0;
 }
 
+BOOST_AUTO_TEST_CASE(vector_bool)
+{
+    std::vector<uint8_t> vec1{1, 0, 0, 1, 1, 1, 0, 0, 0, 0, 1, 0, 0, 1, 1, 0, 0, 0, 1, 1, 1, 1, 0, 1, 0, 0, 1};
+    std::vector<bool> vec2{1, 0, 0, 1, 1, 1, 0, 0, 0, 0, 1, 0, 0, 1, 1, 0, 0, 0, 1, 1, 1, 1, 0, 1, 0, 0, 1};
+
+    BOOST_CHECK(vec1 == std::vector<uint8_t>(vec2.begin(), vec2.end()));
+    BOOST_CHECK(SerializeHash(vec1) == SerializeHash(vec2));
+}
 
 BOOST_AUTO_TEST_CASE(noncanonical)
 {