Add std::optional support to Boost's equality check

Also moved the operators to the bottom of the file since they're less important and to group them together.

Co-authored-by: Hodlinator <172445034+hodlinator@users.noreply.github.com>
Co-authored-by: stickies-v <stickies-v@protonmail.com>

src/test/util/setup_common.cpp

@@ -78,24 +78,6 @@ constexpr inline auto TEST_DIR_PATH_ELEMENT{"test_common bitcoin"}; // Includes
 /** Random context to get unique temp data dirs. Separate from m_rng, which can be seeded from a const env var */
 static FastRandomContext g_rng_temp_path;
 
-std::ostream& operator<<(std::ostream& os, const arith_uint256& num)
-{
-    os << num.ToString();
-    return os;
-}
-
-std::ostream& operator<<(std::ostream& os, const uint160& num)
-{
-    os << num.ToString();
-    return os;
-}
-
-std::ostream& operator<<(std::ostream& os, const uint256& num)
-{
-    os << num.ToString();
-    return os;
-}
-
 struct NetworkSetup
 {
     NetworkSetup()
@@ -606,3 +588,18 @@ CBlock getBlock13b8a()
     stream >> TX_WITH_WITNESS(block);
     return block;
 }
+
+std::ostream& operator<<(std::ostream& os, const arith_uint256& num)
+{
+    return os << num.ToString();
+}
+
+std::ostream& operator<<(std::ostream& os, const uint160& num)
+{
+    return os << num.ToString();
+}
+
+std::ostream& operator<<(std::ostream& os, const uint256& num)
+{
+    return os << num.ToString();
+}

src/test/util/setup_common.h

@@ -10,6 +10,8 @@
 #include <key.h>
 #include <node/caches.h>
 #include <node/context.h> // IWYU pragma: export
+#include <optional>
+#include <ostream>
 #include <primitives/transaction.h>
 #include <pubkey.h>
 #include <stdexcept>
@@ -29,6 +31,8 @@ class arith_uint256;
 class CFeeRate;
 class Chainstate;
 class FastRandomContext;
+class uint160;
+class uint256;
 
 /** This is connected to the logger. Can be used to redirect logs to any other log */
 extern const std::function<void(const std::string&)> G_TEST_LOG_FUN;
@@ -39,15 +43,6 @@ extern const std::function<std::vector<const char*>()> G_TEST_COMMAND_LINE_ARGUM
 /** Retrieve the unit test name. */
 extern const std::function<std::string()> G_TEST_GET_FULL_NAME;
 
-// Enable BOOST_CHECK_EQUAL for enum class types
-namespace std {
-template <typename T>
-std::ostream& operator<<(typename std::enable_if<std::is_enum<T>::value, std::ostream>::type& stream, const T& e)
-{
-    return stream << static_cast<typename std::underlying_type<T>::type>(e);
-}
-} // namespace std
-
 static constexpr CAmount CENT{1000000};
 
 struct TestOpts {
@@ -250,10 +245,26 @@ std::unique_ptr<T> MakeNoLogFileContext(const ChainType chain_type = ChainType::
 
 CBlock getBlock13b8a();
 
-// Make types usable in BOOST_CHECK_*
+// Make types usable in BOOST_CHECK_* @{
+namespace std {
+template <typename T> requires std::is_enum_v<T>
+inline std::ostream& operator<<(std::ostream& os, const T& e)
+{
+    return os << static_cast<std::underlying_type_t<T>>(e);
+}
+
+template <typename T>
+inline std::ostream& operator<<(std::ostream& os, const std::optional<T>& v)
+{
+    return v ? os << *v
+             : os << "std::nullopt";
+}
+} // namespace std
+
 std::ostream& operator<<(std::ostream& os, const arith_uint256& num);
 std::ostream& operator<<(std::ostream& os, const uint160& num);
 std::ostream& operator<<(std::ostream& os, const uint256& num);
+// @}
 
 /**
  * BOOST_CHECK_EXCEPTION predicates to check the specific validation error.