refactor: replace boost::variant with std::variant

Author: div72

src/base58.h

@@ -15,12 +15,14 @@
 #ifndef BITCOIN_BASE58_H
 #define BITCOIN_BASE58_H
 
-#include <string>
-#include <vector>
 #include "bignum.h"
 #include "key.h"
 #include "script.h"
 
+#include <string>
+#include <variant>
+#include <vector>
+
 static const char* pszBase58 = "123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz";
 
 // Encode a byte sequence as a base58-encoded string
@@ -260,7 +262,7 @@ class CBase58Data
  * The data vector contains RIPEMD160(SHA256(cscript)), where cscript is the serialized redemption script.
  */
 class CBitcoinAddress;
-class CBitcoinAddressVisitor : public boost::static_visitor<bool>
+class CBitcoinAddressVisitor
 {
 private:
     CBitcoinAddress *addr;
@@ -295,7 +297,7 @@ class CBitcoinAddress : public CBase58Data
 
     bool Set(const CTxDestination &dest)
     {
-        return boost::apply_visitor(CBitcoinAddressVisitor(this), dest);
+        return std::visit(CBitcoinAddressVisitor(this), dest);
     }
 
     bool IsValid() const

src/gridcoin/cpid.cpp

@@ -6,7 +6,6 @@
 #include "util.h"
 
 #include <algorithm>
-#include <boost/variant/apply_visitor.hpp>
 #include <openssl/md5.h>
 
 using namespace GRC;
@@ -15,7 +14,7 @@ namespace {
 //!
 //! \brief Gets the string representation of a mining ID object.
 //!
-struct MiningIdToStringVisitor : boost::static_visitor<std::string>
+struct MiningIdToStringVisitor
 {
     //!
     //! \brief Call the mining ID variant type's \c ToString() method directly.
@@ -117,7 +116,7 @@ MiningId MiningId::Parse(const std::string& input)
 
 std::string MiningId::ToString() const
 {
-    return boost::apply_visitor(MiningIdToStringVisitor(), m_variant);
+    return std::visit(MiningIdToStringVisitor(), m_variant);
 }
 
 // -----------------------------------------------------------------------------

src/gridcoin/cpid.h

@@ -8,10 +8,9 @@
 
 #include <array>
 #include <boost/optional.hpp>
-#include <boost/variant/get.hpp>
-#include <boost/variant/variant.hpp>
 #include <string>
 #include <vector>
+#include <variant>
 
 namespace GRC {
 //!
@@ -299,12 +298,12 @@ class MiningId
     //!
     bool operator==(const MiningId& other) const
     {
-        if (m_variant.which() != other.m_variant.which()) {
+        if (m_variant.index() != other.m_variant.index()) {
             return false;
         }
 
         if (Which() == Kind::CPID) {
-            return *this == boost::get<Cpid>(other.m_variant);
+            return *this == std::get<Cpid>(other.m_variant);
         }
 
         return true;
@@ -333,7 +332,7 @@ class MiningId
     bool operator==(const Cpid& other) const
     {
         return Which() == Kind::CPID
-            && boost::get<Cpid>(m_variant) == other;
+            && std::get<Cpid>(m_variant) == other;
     }
 
     //!
@@ -356,7 +355,7 @@ class MiningId
     //!
     Kind Which() const
     {
-        return static_cast<Kind>(m_variant.which());
+        return static_cast<Kind>(m_variant.index());
     }
 
     //!
@@ -381,7 +380,7 @@ class MiningId
             return boost::none;
         }
 
-        return boost::get<Cpid>(m_variant);
+        return std::get<Cpid>(m_variant);
     }
 
     //!
@@ -400,12 +399,12 @@ class MiningId
     template<typename Stream>
     void Serialize(Stream& stream) const
     {
-        unsigned char kind = m_variant.which();
+        unsigned char kind = m_variant.index();
 
         ::Serialize(stream, kind);
 
         if (static_cast<Kind>(kind) == Kind::CPID) {
-            boost::get<Cpid>(m_variant).Serialize(stream);
+            std::get<Cpid>(m_variant).Serialize(stream);
         }
     }
 
@@ -443,7 +442,7 @@ class MiningId
     //!
     //! \brief Stores the various states that a mining ID may exist in.
     //!
-    boost::variant<Invalid, Investor, Cpid> m_variant;
+    std::variant<Invalid, Investor, Cpid> m_variant;
 }; // MiningId
 } // namespace GRC
 

src/gridcoin/researcher.cpp

@@ -1048,26 +1048,26 @@ AdvertiseBeaconResult::AdvertiseBeaconResult(const BeaconError error)
 
 CPubKey* AdvertiseBeaconResult::TryPublicKey()
 {
-    if (m_result.which() == 0) {
-        return &boost::get<CPubKey>(m_result);
+    if (m_result.index() == 0) {
+        return &std::get<CPubKey>(m_result);
     }
 
     return nullptr;
 }
 
 const CPubKey* AdvertiseBeaconResult::TryPublicKey() const
 {
-    if (m_result.which() == 0) {
-        return &boost::get<CPubKey>(m_result);
+    if (m_result.index() == 0) {
+        return &std::get<CPubKey>(m_result);
     }
 
     return nullptr;
 }
 
 BeaconError AdvertiseBeaconResult::Error() const
 {
-    if (m_result.which() > 0) {
-        return boost::get<BeaconError>(m_result);
+    if (m_result.index() > 0) {
+        return std::get<BeaconError>(m_result);
     }
 
     return BeaconError::NONE;

src/gridcoin/researcher.h

@@ -8,8 +8,6 @@
 #include "key.h"
 #include "gridcoin/cpid.h"
 
-#include <boost/variant/get.hpp>
-#include <boost/variant/variant.hpp>
 #include <map>
 #include <memory>
 #include <string>
@@ -309,7 +307,7 @@ class AdvertiseBeaconResult
     //! \brief Contains the beacon public key if advertisement succeeded or
     //! the error result if it did not.
     //!
-    boost::variant<CPubKey, BeaconError> m_result;
+    std::variant<CPubKey, BeaconError> m_result;
 };
 
 //!

src/gridcoin/superblock.cpp

@@ -11,7 +11,6 @@
 #include "util.h"
 #include "util/reverse_iterator.h"
 
-#include <boost/variant/apply_visitor.hpp>
 #include <openssl/md5.h>
 
 using namespace GRC;
@@ -475,7 +474,7 @@ class LegacySuperblockParser
 //!
 //! \brief Gets the string representation of a quorum hash object.
 //!
-struct QuorumHashToStringVisitor : boost::static_visitor<std::string>
+struct QuorumHashToStringVisitor
 {
     //!
     //! \brief Get the string representation of an invalid or empty quorum hash.
@@ -1016,7 +1015,7 @@ QuorumHash::QuorumHash(const std::vector<unsigned char>& bytes) : QuorumHash()
         m_hash = uint256(bytes);
     } else if (bytes.size() == sizeof(Md5Sum)) {
         m_hash = Md5Sum();
-        std::copy(bytes.begin(), bytes.end(), boost::get<Md5Sum>(m_hash).begin());
+        std::copy(bytes.begin(), bytes.end(), std::get<Md5Sum>(m_hash).begin());
     }
 }
 
@@ -1081,7 +1080,7 @@ QuorumHash QuorumHash::Parse(const std::string& hex)
 
 bool QuorumHash::operator==(const QuorumHash& other) const
 {
-    if (m_hash.which() != other.m_hash.which()) {
+    if (m_hash.index() != other.m_hash.index()) {
         return false;
     }
 
@@ -1090,12 +1089,12 @@ bool QuorumHash::operator==(const QuorumHash& other) const
             return true;
 
         case Kind::SHA256:
-            return boost::get<uint256>(m_hash)
-                == boost::get<uint256>(other.m_hash);
+            return std::get<uint256>(m_hash)
+                == std::get<uint256>(other.m_hash);
 
         case Kind::MD5:
-            return boost::get<Md5Sum>(m_hash)
-                == boost::get<Md5Sum>(other.m_hash);
+            return std::get<Md5Sum>(m_hash)
+                == std::get<Md5Sum>(other.m_hash);
     }
 
     return false;
@@ -1109,7 +1108,7 @@ bool QuorumHash::operator!=(const QuorumHash& other) const
 bool QuorumHash::operator==(const uint256& other) const
 {
     return Which() == Kind::SHA256
-        && boost::get<uint256>(m_hash) == other;
+        && std::get<uint256>(m_hash) == other;
 }
 
 bool QuorumHash::operator!=(const uint256& other) const
@@ -1125,13 +1124,13 @@ bool QuorumHash::operator==(const std::string& other) const
 
         case Kind::SHA256:
             return other.size() == sizeof(uint256) * 2
-                && boost::get<uint256>(m_hash) == uint256S(other);
+                && std::get<uint256>(m_hash) == uint256S(other);
 
         case Kind::MD5:
             return other.size() == sizeof(Md5Sum) * 2
                 && std::equal(
-                    boost::get<Md5Sum>(m_hash).begin(),
-                    boost::get<Md5Sum>(m_hash).end(),
+                    std::get<Md5Sum>(m_hash).begin(),
+                    std::get<Md5Sum>(m_hash).end(),
                     ParseHex(other).begin());
     }
 
@@ -1145,7 +1144,7 @@ bool QuorumHash::operator!=(const std::string&other) const
 
 QuorumHash::Kind QuorumHash::Which() const
 {
-    return static_cast<Kind>(m_hash.which());
+    return static_cast<Kind>(m_hash.index());
 }
 
 bool QuorumHash::Valid() const
@@ -1159,15 +1158,15 @@ const unsigned char* QuorumHash::Raw() const
         case Kind::INVALID:
             return nullptr;
         case Kind::SHA256:
-            return boost::get<uint256>(m_hash).begin();
+            return std::get<uint256>(m_hash).begin();
         case Kind::MD5:
-            return boost::get<Md5Sum>(m_hash).data();
+            return std::get<Md5Sum>(m_hash).data();
     }
 
     return nullptr;
 }
 
 std::string QuorumHash::ToString() const
 {
-    return boost::apply_visitor(QuorumHashToStringVisitor(), m_hash);
+    return std::visit(QuorumHashToStringVisitor(), m_hash);
 }

src/gridcoin/superblock.h

@@ -11,7 +11,6 @@
 #include "uint256.h"
 
 #include <boost/optional.hpp>
-#include <boost/variant/variant.hpp>
 #include <iterator>
 #include <memory>
 #include <string>
@@ -171,7 +170,7 @@ class QuorumHash
     template<typename Stream>
     void Serialize(Stream& stream) const
     {
-        unsigned char kind = m_hash.which();
+        unsigned char kind = m_hash.index();
 
         ::Serialize(stream, kind);
 
@@ -180,11 +179,11 @@ class QuorumHash
                 break; // Suppress warning.
 
             case Kind::SHA256:
-                boost::get<uint256>(m_hash).Serialize(stream);
+                std::get<uint256>(m_hash).Serialize(stream);
                 break;
 
             case Kind::MD5: {
-                const Md5Sum& hash = boost::get<Md5Sum>(m_hash);
+                const Md5Sum& hash = std::get<Md5Sum>(m_hash);
 
                 stream.write(CharCast(hash.data()), hash.size());
                 break;
@@ -234,7 +233,7 @@ class QuorumHash
     //! CONSENSUS: Do not remove or reorder the types in this variant. This
     //! class relies on the type ordinality to tag serialized values.
     //!
-    boost::variant<Invalid, uint256, Md5Sum> m_hash;
+    std::variant<Invalid, uint256, Md5Sum> m_hash;
 }; // QuorumHash
 
 //!

src/gridcoin/voting/builders.cpp

@@ -147,7 +147,7 @@ class CoinPicker
     //! \brief Adds outputs for an address only when an address represents
     //! a pay-to-public-key or pay-to-public-key-hash destination.
     //!
-    class PubkeyDestinationFilter : public boost::static_visitor<void>
+    class PubkeyDestinationFilter
     {
     public:
         //!
@@ -232,7 +232,7 @@ class CoinPicker
             // more advanced redemption scripts like multisig yet:
             //
             auto filter = std::bind(pubkey_filter, std::placeholders::_1, txo);
-            boost::apply_visitor(filter, dest);
+            std::visit(filter, dest);
         }
 
         return by_address;