Declare single-argument (non-converting) constructors "explicit"

In order to avoid unintended implicit conversions.

Author: practicalswift

src/addrdb.h

@@ -37,7 +37,7 @@ class CBanEntry
         SetNull();
     }
 
-    CBanEntry(int64_t nCreateTimeIn)
+    explicit CBanEntry(int64_t nCreateTimeIn)
     {
         SetNull();
         nCreateTime = nCreateTimeIn;

src/base58.cpp

@@ -218,7 +218,7 @@ class CBitcoinAddressVisitor : public boost::static_visitor<bool>
     CBitcoinAddress* addr;
 
 public:
-    CBitcoinAddressVisitor(CBitcoinAddress* addrIn) : addr(addrIn) {}
+    explicit CBitcoinAddressVisitor(CBitcoinAddress* addrIn) : addr(addrIn) {}
 
     bool operator()(const CKeyID& id) const { return addr->Set(id); }
     bool operator()(const CScriptID& id) const { return addr->Set(id); }

src/bench/checkqueue.cpp

@@ -67,7 +67,7 @@ static void CCheckQueueSpeedPrevectorJob(benchmark::State& state)
         prevector<PREVECTOR_SIZE, uint8_t> p;
         PrevectorJob(){
         }
-        PrevectorJob(FastRandomContext& insecure_rand){
+        explicit PrevectorJob(FastRandomContext& insecure_rand){
             p.resize(insecure_rand.randrange(PREVECTOR_SIZE*2));
         }
         bool operator()()

src/blockencodings.h

@@ -16,7 +16,7 @@ struct TransactionCompressor {
 private:
     CTransactionRef& tx;
 public:
-    TransactionCompressor(CTransactionRef& txIn) : tx(txIn) {}
+    explicit TransactionCompressor(CTransactionRef& txIn) : tx(txIn) {}
 
     ADD_SERIALIZE_METHODS;
 
@@ -75,7 +75,7 @@ class BlockTransactions {
     std::vector<CTransactionRef> txn;
 
     BlockTransactions() {}
-    BlockTransactions(const BlockTransactionsRequest& req) :
+    explicit BlockTransactions(const BlockTransactionsRequest& req) :
         blockhash(req.blockhash), txn(req.indexes.size()) {}
 
     ADD_SERIALIZE_METHODS;
@@ -198,7 +198,7 @@ class PartiallyDownloadedBlock {
     CTxMemPool* pool;
 public:
     CBlockHeader header;
-    PartiallyDownloadedBlock(CTxMemPool* poolIn) : pool(poolIn) {}
+    explicit PartiallyDownloadedBlock(CTxMemPool* poolIn) : pool(poolIn) {}
 
     // extra_txn is a list of extra transactions to look at, in <witness hash, reference> form
     ReadStatus InitData(const CBlockHeaderAndShortTxIDs& cmpctblock, const std::vector<std::pair<uint256, CTransactionRef>>& extra_txn);

src/chain.h

@@ -247,7 +247,7 @@ class CBlockIndex
         SetNull();
     }
 
-    CBlockIndex(const CBlockHeader& block)
+    explicit CBlockIndex(const CBlockHeader& block)
     {
         SetNull();
 

src/checkqueue.h

@@ -131,7 +131,7 @@ class CCheckQueue
     boost::mutex ControlMutex;
 
     //! Create a new check queue
-    CCheckQueue(unsigned int nBatchSizeIn) : nIdle(0), nTotal(0), fAllOk(true), nTodo(0), fQuit(false), nBatchSize(nBatchSizeIn) {}
+    explicit CCheckQueue(unsigned int nBatchSizeIn) : nIdle(0), nTotal(0), fAllOk(true), nTodo(0), fQuit(false), nBatchSize(nBatchSizeIn) {}
 
     //! Worker thread
     void Thread()

src/compressor.h

@@ -53,7 +53,7 @@ class CScriptCompressor
     unsigned int GetSpecialSize(unsigned int nSize) const;
     bool Decompress(unsigned int nSize, const std::vector<unsigned char> &out);
 public:
-    CScriptCompressor(CScript &scriptIn) : script(scriptIn) { }
+    explicit CScriptCompressor(CScript &scriptIn) : script(scriptIn) { }
 
     template<typename Stream>
     void Serialize(Stream &s) const {
@@ -99,7 +99,7 @@ class CTxOutCompressor
     static uint64_t CompressAmount(uint64_t nAmount);
     static uint64_t DecompressAmount(uint64_t nAmount);
 
-    CTxOutCompressor(CTxOut &txoutIn) : txout(txoutIn) { }
+    explicit CTxOutCompressor(CTxOut &txoutIn) : txout(txoutIn) { }
 
     ADD_SERIALIZE_METHODS;
 

src/crypto/aes.h

@@ -22,7 +22,7 @@ class AES128Encrypt
     AES128_ctx ctx;
 
 public:
-    AES128Encrypt(const unsigned char key[16]);
+    explicit AES128Encrypt(const unsigned char key[16]);
     ~AES128Encrypt();
     void Encrypt(unsigned char ciphertext[16], const unsigned char plaintext[16]) const;
 };
@@ -34,7 +34,7 @@ class AES128Decrypt
     AES128_ctx ctx;
 
 public:
-    AES128Decrypt(const unsigned char key[16]);
+    explicit AES128Decrypt(const unsigned char key[16]);
     ~AES128Decrypt();
     void Decrypt(unsigned char plaintext[16], const unsigned char ciphertext[16]) const;
 };
@@ -46,7 +46,7 @@ class AES256Encrypt
     AES256_ctx ctx;
 
 public:
-    AES256Encrypt(const unsigned char key[32]);
+    explicit AES256Encrypt(const unsigned char key[32]);
     ~AES256Encrypt();
     void Encrypt(unsigned char ciphertext[16], const unsigned char plaintext[16]) const;
 };
@@ -58,7 +58,7 @@ class AES256Decrypt
     AES256_ctx ctx;
 
 public:
-    AES256Decrypt(const unsigned char key[32]);
+    explicit AES256Decrypt(const unsigned char key[32]);
     ~AES256Decrypt();
     void Decrypt(unsigned char plaintext[16], const unsigned char ciphertext[16]) const;
 };

src/cuckoocache.h

@@ -58,7 +58,7 @@ class bit_packed_atomic_flags
      * @post All calls to bit_is_set (without subsequent bit_unset) will return
      * true.
      */
-    bit_packed_atomic_flags(uint32_t size)
+    explicit bit_packed_atomic_flags(uint32_t size)
     {
         // pad out the size if needed
         size = (size + 7) / 8;

src/dbwrapper.h

@@ -22,7 +22,7 @@ static const size_t DBWRAPPER_PREALLOC_VALUE_SIZE = 1024;
 class dbwrapper_error : public std::runtime_error
 {
 public:
-    dbwrapper_error(const std::string& msg) : std::runtime_error(msg) {}
+    explicit dbwrapper_error(const std::string& msg) : std::runtime_error(msg) {}
 };
 
 class CDBWrapper;
@@ -61,7 +61,7 @@ class CDBBatch
     /**
      * @param[in] _parent   CDBWrapper that this batch is to be submitted to
      */
-    CDBBatch(const CDBWrapper &_parent) : parent(_parent), ssKey(SER_DISK, CLIENT_VERSION), ssValue(SER_DISK, CLIENT_VERSION), size_estimate(0) { };
+    explicit CDBBatch(const CDBWrapper &_parent) : parent(_parent), ssKey(SER_DISK, CLIENT_VERSION), ssValue(SER_DISK, CLIENT_VERSION), size_estimate(0) { };
 
     void Clear()
     {