test: Use throwing variant accessor

It does not matter if the tests fail due to a BOOST_CHECK failure or
due to a thrown exception. Prefer the exception because it is less
code.

Example fail with the throwing accessor:

unknown location(0): fatal error: in "script_standard_tests/script_standard_ExtractDestinations": std::bad_variant_access: std::get: wrong index for variant
test/script_standard_tests.cpp(314): last checkpoint

*** 1 failure is detected in the test module "Bitcoin Core Test Suite"

Author: MarcoFalke

src/test/script_standard_tests.cpp

@@ -199,23 +199,20 @@ BOOST_AUTO_TEST_CASE(script_standard_ExtractDestination)
     s.clear();
     s << ToByteVector(pubkey) << OP_CHECKSIG;
     BOOST_CHECK(ExtractDestination(s, address));
-    BOOST_CHECK(std::get_if<PKHash>(&address) &&
-                *std::get_if<PKHash>(&address) == PKHash(pubkey));
+    BOOST_CHECK(std::get<PKHash>(address) == PKHash(pubkey));
 
     // TxoutType::PUBKEYHASH
     s.clear();
     s << OP_DUP << OP_HASH160 << ToByteVector(pubkey.GetID()) << OP_EQUALVERIFY << OP_CHECKSIG;
     BOOST_CHECK(ExtractDestination(s, address));
-    BOOST_CHECK(std::get_if<PKHash>(&address) &&
-                *std::get_if<PKHash>(&address) == PKHash(pubkey));
+    BOOST_CHECK(std::get<PKHash>(address) == PKHash(pubkey));
 
     // TxoutType::SCRIPTHASH
     CScript redeemScript(s); // initialize with leftover P2PKH script
     s.clear();
     s << OP_HASH160 << ToByteVector(CScriptID(redeemScript)) << OP_EQUAL;
     BOOST_CHECK(ExtractDestination(s, address));
-    BOOST_CHECK(std::get_if<ScriptHash>(&address) &&
-                *std::get_if<ScriptHash>(&address) == ScriptHash(redeemScript));
+    BOOST_CHECK(std::get<ScriptHash>(address) == ScriptHash(redeemScript));
 
     // TxoutType::MULTISIG
     s.clear();
@@ -233,15 +230,15 @@ BOOST_AUTO_TEST_CASE(script_standard_ExtractDestination)
     BOOST_CHECK(ExtractDestination(s, address));
     WitnessV0KeyHash keyhash;
     CHash160().Write(pubkey).Finalize(keyhash);
-    BOOST_CHECK(std::get_if<WitnessV0KeyHash>(&address) && *std::get_if<WitnessV0KeyHash>(&address) == keyhash);
+    BOOST_CHECK(std::get<WitnessV0KeyHash>(address) == keyhash);
 
     // TxoutType::WITNESS_V0_SCRIPTHASH
     s.clear();
     WitnessV0ScriptHash scripthash;
     CSHA256().Write(redeemScript.data(), redeemScript.size()).Finalize(scripthash.begin());
     s << OP_0 << ToByteVector(scripthash);
     BOOST_CHECK(ExtractDestination(s, address));
-    BOOST_CHECK(std::get_if<WitnessV0ScriptHash>(&address) && *std::get_if<WitnessV0ScriptHash>(&address) == scripthash);
+    BOOST_CHECK(std::get<WitnessV0ScriptHash>(address) == scripthash);
 
     // TxoutType::WITNESS_UNKNOWN with unknown version
     s.clear();
@@ -251,7 +248,7 @@ BOOST_AUTO_TEST_CASE(script_standard_ExtractDestination)
     unk.length = 33;
     unk.version = 1;
     std::copy(pubkey.begin(), pubkey.end(), unk.program);
-    BOOST_CHECK(std::get_if<WitnessUnknown>(&address) && *std::get_if<WitnessUnknown>(&address) == unk);
+    BOOST_CHECK(std::get<WitnessUnknown>(address) == unk);
 }
 
 BOOST_AUTO_TEST_CASE(script_standard_ExtractDestinations)
@@ -275,8 +272,7 @@ BOOST_AUTO_TEST_CASE(script_standard_ExtractDestinations)
     BOOST_CHECK_EQUAL(whichType, TxoutType::PUBKEY);
     BOOST_CHECK_EQUAL(addresses.size(), 1U);
     BOOST_CHECK_EQUAL(nRequired, 1);
-    BOOST_CHECK(std::get_if<PKHash>(&addresses[0]) &&
-                *std::get_if<PKHash>(&addresses[0]) == PKHash(pubkeys[0]));
+    BOOST_CHECK(std::get<PKHash>(addresses[0]) == PKHash(pubkeys[0]));
 
     // TxoutType::PUBKEYHASH
     s.clear();
@@ -285,8 +281,7 @@ BOOST_AUTO_TEST_CASE(script_standard_ExtractDestinations)
     BOOST_CHECK_EQUAL(whichType, TxoutType::PUBKEYHASH);
     BOOST_CHECK_EQUAL(addresses.size(), 1U);
     BOOST_CHECK_EQUAL(nRequired, 1);
-    BOOST_CHECK(std::get_if<PKHash>(&addresses[0]) &&
-                *std::get_if<PKHash>(&addresses[0]) == PKHash(pubkeys[0]));
+    BOOST_CHECK(std::get<PKHash>(addresses[0]) == PKHash(pubkeys[0]));
 
     // TxoutType::SCRIPTHASH
     CScript redeemScript(s); // initialize with leftover P2PKH script
@@ -296,8 +291,7 @@ BOOST_AUTO_TEST_CASE(script_standard_ExtractDestinations)
     BOOST_CHECK_EQUAL(whichType, TxoutType::SCRIPTHASH);
     BOOST_CHECK_EQUAL(addresses.size(), 1U);
     BOOST_CHECK_EQUAL(nRequired, 1);
-    BOOST_CHECK(std::get_if<ScriptHash>(&addresses[0]) &&
-                *std::get_if<ScriptHash>(&addresses[0]) == ScriptHash(redeemScript));
+    BOOST_CHECK(std::get<ScriptHash>(addresses[0]) == ScriptHash(redeemScript));
 
     // TxoutType::MULTISIG
     s.clear();
@@ -309,10 +303,8 @@ BOOST_AUTO_TEST_CASE(script_standard_ExtractDestinations)
     BOOST_CHECK_EQUAL(whichType, TxoutType::MULTISIG);
     BOOST_CHECK_EQUAL(addresses.size(), 2U);
     BOOST_CHECK_EQUAL(nRequired, 2);
-    BOOST_CHECK(std::get_if<PKHash>(&addresses[0]) &&
-                *std::get_if<PKHash>(&addresses[0]) == PKHash(pubkeys[0]));
-    BOOST_CHECK(std::get_if<PKHash>(&addresses[1]) &&
-                *std::get_if<PKHash>(&addresses[1]) == PKHash(pubkeys[1]));
+    BOOST_CHECK(std::get<PKHash>(addresses[0]) == PKHash(pubkeys[0]));
+    BOOST_CHECK(std::get<PKHash>(addresses[1]) == PKHash(pubkeys[1]));
 
     // TxoutType::NULL_DATA
     s.clear();