From e00114b3f157d3da5a610d10345a210c9a46eca5 Mon Sep 17 00:00:00 2001
From: Jonathan Hui <jonhui@nestlabs.com>
Date: Wed, 20 Mar 2019 11:23:57 -0700
Subject: [PATCH] [style] mark single-arg constructors as explicit (#3705)

Avoids unintentional implicit conversions.
---
 src/cli/cli.cpp                     | 2 +-
 src/cli/cli.hpp                     | 2 +-
 src/cli/cli_coap.hpp                | 2 +-
 src/cli/cli_coap_secure.hpp         | 2 +-
 src/cli/cli_console.hpp             | 2 +-
 src/cli/cli_dataset.hpp             | 2 +-
 src/cli/cli_server.hpp              | 2 +-
 src/cli/cli_uart.hpp                | 2 +-
 src/cli/cli_udp.hpp                 | 2 +-
 src/core/api/link_api.cpp           | 3 ++-
 src/core/api/thread_api.cpp         | 4 ++--
 src/core/coap/coap.hpp              | 2 +-
 src/core/common/crc16.hpp           | 2 +-
 src/core/common/locator.hpp         | 4 ++--
 src/core/common/message.hpp         | 2 +-
 src/core/common/settings.hpp        | 2 +-
 src/core/common/string.hpp          | 2 +-
 src/core/common/timer.hpp           | 4 ++--
 src/core/mac/channel_mask.hpp       | 2 +-
 src/core/mac/mac.cpp                | 2 +-
 src/core/meshcop/dataset.hpp        | 2 +-
 src/core/meshcop/joiner.cpp         | 4 ++--
 src/core/net/dns_client.hpp         | 2 +-
 src/core/net/sntp_client.hpp        | 2 +-
 src/core/thread/announce_sender.cpp | 2 +-
 src/core/thread/network_data.hpp    | 2 +-
 src/core/thread/router_table.hpp    | 6 +++---
 src/core/utils/channel_monitor.hpp  | 2 +-
 src/ncp/ncp_base.hpp                | 2 +-
 src/ncp/ncp_spi.hpp                 | 4 ++--
 src/ncp/ncp_uart.hpp                | 2 +-
 src/ncp/spinel_encoder.hpp          | 2 +-
 32 files changed, 40 insertions(+), 39 deletions(-)

diff --git a/src/cli/cli.cpp b/src/cli/cli.cpp
index 4faaf2775..5cca37200 100644
--- a/src/cli/cli.cpp
+++ b/src/cli/cli.cpp
@@ -263,7 +263,7 @@ template <class T> class otPtr
     T *ptr;
 
 public:
-    otPtr(T *_ptr)
+    explicit otPtr(T *_ptr)
         : ptr(_ptr)
     {
     }
diff --git a/src/cli/cli.hpp b/src/cli/cli.hpp
index a7e6aa49c..fc8960a1b 100644
--- a/src/cli/cli.hpp
+++ b/src/cli/cli.hpp
@@ -110,7 +110,7 @@ public:
      *
      * @param[in]  aInstance  The OpenThread instance structure.
      */
-    Interpreter(Instance *aInstance);
+    explicit Interpreter(Instance *aInstance);
 
     /**
      * This method interprets a CLI command.
diff --git a/src/cli/cli_coap.hpp b/src/cli/cli_coap.hpp
index a469aa41a..0728222c8 100644
--- a/src/cli/cli_coap.hpp
+++ b/src/cli/cli_coap.hpp
@@ -58,7 +58,7 @@ public:
      * @param[in]  aInterpreter  The CLI interpreter.
      *
      */
-    Coap(Interpreter &aInterpreter);
+    explicit Coap(Interpreter &aInterpreter);
 
     /**
      * This method interprets a list of CLI arguments.
diff --git a/src/cli/cli_coap_secure.hpp b/src/cli/cli_coap_secure.hpp
index c723d0360..0f0d12be9 100644
--- a/src/cli/cli_coap_secure.hpp
+++ b/src/cli/cli_coap_secure.hpp
@@ -64,7 +64,7 @@ public:
      * @param[in]  aInterpreter  The CLI interpreter.
      *
      */
-    CoapSecure(Interpreter &aInterpreter);
+    explicit CoapSecure(Interpreter &aInterpreter);
 
     /**
      * This method interprets a list of CLI arguments.
diff --git a/src/cli/cli_console.hpp b/src/cli/cli_console.hpp
index aa12840f5..80587c9c8 100644
--- a/src/cli/cli_console.hpp
+++ b/src/cli/cli_console.hpp
@@ -57,7 +57,7 @@ public:
      * @param[in]  aInstance  The OpenThread instance structure.
      *
      */
-    Console(Instance *aInstance);
+    explicit Console(Instance *aInstance);
 
     /**
      * This method delivers raw characters to the client.
diff --git a/src/cli/cli_dataset.hpp b/src/cli/cli_dataset.hpp
index f1b8d0e01..436d0485b 100644
--- a/src/cli/cli_dataset.hpp
+++ b/src/cli/cli_dataset.hpp
@@ -52,7 +52,7 @@ class Interpreter;
 class Dataset
 {
 public:
-    Dataset(Interpreter &aInterpreter)
+    explicit Dataset(Interpreter &aInterpreter)
         : mInterpreter(aInterpreter)
     {
     }
diff --git a/src/cli/cli_server.hpp b/src/cli/cli_server.hpp
index bc1297ab8..0744aa61f 100644
--- a/src/cli/cli_server.hpp
+++ b/src/cli/cli_server.hpp
@@ -48,7 +48,7 @@ namespace Cli {
 class Server
 {
 public:
-    Server(Instance *aInstance)
+    explicit Server(Instance *aInstance)
         : mInterpreter(aInstance)
     {
     }
diff --git a/src/cli/cli_uart.hpp b/src/cli/cli_uart.hpp
index ccf85add2..f5a7b747a 100644
--- a/src/cli/cli_uart.hpp
+++ b/src/cli/cli_uart.hpp
@@ -57,7 +57,7 @@ public:
      * @param[in]  aInstance  The OpenThread instance structure.
      *
      */
-    Uart(Instance *aInstance);
+    explicit Uart(Instance *aInstance);
 
     /**
      * This method delivers raw characters to the client.
diff --git a/src/cli/cli_udp.hpp b/src/cli/cli_udp.hpp
index cb18f38d1..eeb1f33ad 100644
--- a/src/cli/cli_udp.hpp
+++ b/src/cli/cli_udp.hpp
@@ -56,7 +56,7 @@ public:
      * @param[in]  aInterpreter  The CLI interpreter.
      *
      */
-    UdpExample(Interpreter &aInterpreter);
+    explicit UdpExample(Interpreter &aInterpreter);
 
     /**
      * This method interprets a list of CLI arguments.
diff --git a/src/core/api/link_api.cpp b/src/core/api/link_api.cpp
index f55e3a762..ae02f99f8 100644
--- a/src/core/api/link_api.cpp
+++ b/src/core/api/link_api.cpp
@@ -36,6 +36,7 @@
 #include <openthread/link.h>
 
 #include "common/instance.hpp"
+#include "mac/mac.hpp"
 #include "phy/phy.hpp"
 
 using namespace ot;
@@ -101,7 +102,7 @@ otError otLinkSetSupportedChannelMask(otInstance *aInstance, uint32_t aChannelMa
     VerifyOrExit(instance.GetThreadNetif().GetMle().GetRole() == OT_DEVICE_ROLE_DISABLED,
                  error = OT_ERROR_INVALID_STATE);
 
-    instance.GetThreadNetif().GetMac().SetSupportedChannelMask(aChannelMask);
+    instance.GetThreadNetif().GetMac().SetSupportedChannelMask(static_cast<Mac::ChannelMask>(aChannelMask));
 
 exit:
     return error;
diff --git a/src/core/api/thread_api.cpp b/src/core/api/thread_api.cpp
index bba3cba99..5a343ef68 100644
--- a/src/core/api/thread_api.cpp
+++ b/src/core/api/thread_api.cpp
@@ -507,8 +507,8 @@ otError otThreadDiscover(otInstance *             aInstance,
 {
     Instance &instance = *static_cast<Instance *>(aInstance);
 
-    return instance.GetThreadNetif().GetMle().Discover(aScanChannels, aPanId, aJoiner, aEnableEui64Filtering, aCallback,
-                                                       aCallbackContext);
+    return instance.GetThreadNetif().GetMle().Discover(static_cast<Mac::ChannelMask>(aScanChannels), aPanId, aJoiner,
+                                                       aEnableEui64Filtering, aCallback, aCallbackContext);
 }
 
 bool otThreadIsDiscoverInProgress(otInstance *aInstance)
diff --git a/src/core/coap/coap.hpp b/src/core/coap/coap.hpp
index 741b213c5..6d95af45a 100644
--- a/src/core/coap/coap.hpp
+++ b/src/core/coap/coap.hpp
@@ -267,7 +267,7 @@ public:
      * @param[in]  aMessageInfo  The message info containing source endpoint identification.
      *
      */
-    EnqueuedResponseHeader(const Ip6::MessageInfo &aMessageInfo)
+    explicit EnqueuedResponseHeader(const Ip6::MessageInfo &aMessageInfo)
         : mDequeueTime(TimerMilli::GetNow() + TimerMilli::SecToMsec(kExchangeLifetime))
         , mMessageInfo(aMessageInfo)
     {
diff --git a/src/core/common/crc16.hpp b/src/core/common/crc16.hpp
index 2d2ef35dd..fa0a3f199 100644
--- a/src/core/common/crc16.hpp
+++ b/src/core/common/crc16.hpp
@@ -59,7 +59,7 @@ public:
      * @param[in]  aPolynomial  The polynomial value.
      *
      */
-    Crc16(Polynomial aPolynomial);
+    explicit Crc16(Polynomial aPolynomial);
 
     /**
      * This method initializes the CRC16 computation.
diff --git a/src/core/common/locator.hpp b/src/core/common/locator.hpp
index f10149f1b..61555cb99 100644
--- a/src/core/common/locator.hpp
+++ b/src/core/common/locator.hpp
@@ -114,7 +114,7 @@ protected:
      * @param[in]  aInstance  A pointer to the otInstance.
      *
      */
-    InstanceLocator(Instance &aInstance)
+    explicit InstanceLocator(Instance &aInstance)
 #if OPENTHREAD_ENABLE_MULTIPLE_INSTANCES
         : mInstance(aInstance)
 #endif
@@ -162,7 +162,7 @@ protected:
      * @param[in]  aOwner   A pointer to the owner object (as `void *`).
      *
      */
-    OwnerLocator(void *aOwner)
+    explicit OwnerLocator(void *aOwner)
 #if OPENTHREAD_ENABLE_MULTIPLE_INSTANCES
         : mOwner(aOwner)
 #endif
diff --git a/src/core/common/message.hpp b/src/core/common/message.hpp
index a4712fc3e..5c640a59b 100644
--- a/src/core/common/message.hpp
+++ b/src/core/common/message.hpp
@@ -1244,7 +1244,7 @@ public:
         }
 
     private:
-        Iterator(Message *aMessage)
+        explicit Iterator(Message *aMessage)
             : mMessage(aMessage)
         {
         }
diff --git a/src/core/common/settings.hpp b/src/core/common/settings.hpp
index 561896ced..ff767844e 100644
--- a/src/core/common/settings.hpp
+++ b/src/core/common/settings.hpp
@@ -402,7 +402,7 @@ public:
          * @param[in]  aInstance  A reference to the OpenThread instance.
          *
          */
-        ChildInfoIterator(Instance &aInstance);
+        explicit ChildInfoIterator(Instance &aInstance);
 
         /**
          * This method resets the iterator to start from the first Child Info entry in the list.
diff --git a/src/core/common/string.hpp b/src/core/common/string.hpp
index 895b0fd9b..99c587fa1 100644
--- a/src/core/common/string.hpp
+++ b/src/core/common/string.hpp
@@ -109,7 +109,7 @@ public:
      * @param[in] ...        Arguments for the format specification.
      *
      */
-    String(const char *aFormat, ...)
+    explicit String(const char *aFormat, ...)
         : mLength(0)
     {
         va_list args;
diff --git a/src/core/common/timer.hpp b/src/core/common/timer.hpp
index 483a79145..3feb5d531 100644
--- a/src/core/common/timer.hpp
+++ b/src/core/common/timer.hpp
@@ -295,7 +295,7 @@ protected:
      * @param[in]  aInstance  A reference to the instance object.
      *
      */
-    TimerScheduler(Instance &aInstance)
+    explicit TimerScheduler(Instance &aInstance)
         : InstanceLocator(aInstance)
         , mHead(NULL)
     {
@@ -351,7 +351,7 @@ public:
      * @param[in]  aInstance  A reference to the instance object.
      *
      */
-    TimerMilliScheduler(Instance &aInstance)
+    explicit TimerMilliScheduler(Instance &aInstance)
         : TimerScheduler(aInstance)
     {
     }
diff --git a/src/core/mac/channel_mask.hpp b/src/core/mac/channel_mask.hpp
index 423649847..29e79ed08 100644
--- a/src/core/mac/channel_mask.hpp
+++ b/src/core/mac/channel_mask.hpp
@@ -92,7 +92,7 @@ public:
      * @param[in]  aMask   A channel mask (as a `uint32_t` bit-vector mask with bit 0 (lsb) -> channel 0, and so on).
      *
      */
-    ChannelMask(uint32_t aMask)
+    explicit ChannelMask(uint32_t aMask)
         : mMask(aMask)
     {
     }
diff --git a/src/core/mac/mac.cpp b/src/core/mac/mac.cpp
index c4ea922fe..bc64f5fbb 100644
--- a/src/core/mac/mac.cpp
+++ b/src/core/mac/mac.cpp
@@ -425,7 +425,7 @@ void Mac::SetSupportedChannelMask(const ChannelMask &aMask)
 {
     ChannelMask newMask = aMask;
 
-    newMask.Intersect(Phy::kSupportedChannels);
+    newMask.Intersect(ChannelMask(Phy::kSupportedChannels));
     VerifyOrExit(newMask != mSupportedChannelMask, GetNotifier().SignalIfFirst(OT_CHANGED_SUPPORTED_CHANNEL_MASK));
 
     mSupportedChannelMask = newMask;
diff --git a/src/core/meshcop/dataset.hpp b/src/core/meshcop/dataset.hpp
index 9aa50727c..e4a8071c8 100644
--- a/src/core/meshcop/dataset.hpp
+++ b/src/core/meshcop/dataset.hpp
@@ -63,7 +63,7 @@ public:
      * @param[in]  aType       The type of the dataset, active or pending.
      *
      */
-    Dataset(const Tlv::Type aType);
+    explicit Dataset(const Tlv::Type aType);
 
     /**
      * This method clears the Dataset.
diff --git a/src/core/meshcop/joiner.cpp b/src/core/meshcop/joiner.cpp
index dbbc96c5e..50207c407 100644
--- a/src/core/meshcop/joiner.cpp
+++ b/src/core/meshcop/joiner.cpp
@@ -127,8 +127,8 @@ otError Joiner::Start(const char *     aPSKd,
 
     memset(mJoinerRouters, 0, sizeof(mJoinerRouters));
 
-    SuccessOrExit(error =
-                      netif.GetMle().Discover(0, netif.GetMac().GetPanId(), true, false, HandleDiscoverResult, this));
+    SuccessOrExit(error = netif.GetMle().Discover(Mac::ChannelMask(0), netif.GetMac().GetPanId(), true, false,
+                                                  HandleDiscoverResult, this));
 
     mVendorName      = aVendorName;
     mVendorModel     = aVendorModel;
diff --git a/src/core/net/dns_client.hpp b/src/core/net/dns_client.hpp
index 14bec05a1..55499297e 100644
--- a/src/core/net/dns_client.hpp
+++ b/src/core/net/dns_client.hpp
@@ -158,7 +158,7 @@ public:
      * @param[in]  aNetif    A reference to the network interface that DNS client should be assigned to.
      *
      */
-    Client(Ip6::Netif &aNetif)
+    explicit Client(Ip6::Netif &aNetif)
         : mSocket(aNetif.GetIp6().GetUdp())
         , mMessageId(0)
         , mRetransmissionTimer(aNetif.GetInstance(), &Client::HandleRetransmissionTimer, this){};
diff --git a/src/core/net/sntp_client.hpp b/src/core/net/sntp_client.hpp
index 31e0c5216..48c133c4e 100644
--- a/src/core/net/sntp_client.hpp
+++ b/src/core/net/sntp_client.hpp
@@ -528,7 +528,7 @@ public:
      * @param[in]  aNetif    A reference to the network interface that SNTP client should be assigned to.
      *
      */
-    Client(Ip6::Netif &aNetif)
+    explicit Client(Ip6::Netif &aNetif)
         : mSocket(aNetif.GetIp6().GetUdp())
         , mRetransmissionTimer(aNetif.GetInstance(), &Client::HandleRetransmissionTimer, this)
         , mUnixEra(0){};
diff --git a/src/core/thread/announce_sender.cpp b/src/core/thread/announce_sender.cpp
index 5a2afea62..4ac092002 100644
--- a/src/core/thread/announce_sender.cpp
+++ b/src/core/thread/announce_sender.cpp
@@ -66,7 +66,7 @@ otError AnnounceSenderBase::SendAnnounce(Mac::ChannelMask aMask, uint8_t aCount,
     VerifyOrExit(aPeriod != 0, error = OT_ERROR_INVALID_ARGS);
     VerifyOrExit(aJitter < aPeriod, error = OT_ERROR_INVALID_ARGS);
 
-    aMask.Intersect(Phy::kSupportedChannels);
+    aMask.Intersect(Mac::ChannelMask(Phy::kSupportedChannels));
     VerifyOrExit(!aMask.IsEmpty(), error = OT_ERROR_INVALID_ARGS);
 
     mChannelMask = aMask;
diff --git a/src/core/thread/network_data.hpp b/src/core/thread/network_data.hpp
index 78ea5590b..6ca2bcbc0 100644
--- a/src/core/thread/network_data.hpp
+++ b/src/core/thread/network_data.hpp
@@ -488,7 +488,7 @@ private:
         };
 
     public:
-        NetworkDataIterator(otNetworkDataIterator *aIterator)
+        explicit NetworkDataIterator(otNetworkDataIterator *aIterator)
             : mIteratorBuffer(reinterpret_cast<uint8_t *>(aIterator))
         {
         }
diff --git a/src/core/thread/router_table.hpp b/src/core/thread/router_table.hpp
index 61ef0c58d..2d626904b 100644
--- a/src/core/thread/router_table.hpp
+++ b/src/core/thread/router_table.hpp
@@ -56,7 +56,7 @@ public:
          * @param[in] aInstance  A reference to the OpenThread instance.
          *
          */
-        Iterator(Instance &aInstance);
+        explicit Iterator(Instance &aInstance);
 
         /**
          * This method resets the iterator to start over.
@@ -118,7 +118,7 @@ public:
      * @param[in]  aInstance  A reference to the OpenThread instance.
      *
      */
-    RouterTable(Instance &aInstance);
+    explicit RouterTable(Instance &aInstance);
 
     /**
      * This method clears the router table.
@@ -371,7 +371,7 @@ public:
     class Iterator
     {
     public:
-        Iterator(Instance &) {}
+        explicit Iterator(Instance &) {}
         void    Reset(void) {}
         bool    IsDone(void) const { return true; }
         void    Advance(void) {}
diff --git a/src/core/utils/channel_monitor.hpp b/src/core/utils/channel_monitor.hpp
index 0a631d63c..487837f40 100644
--- a/src/core/utils/channel_monitor.hpp
+++ b/src/core/utils/channel_monitor.hpp
@@ -102,7 +102,7 @@ public:
      * @param[in]  aInstance     A reference to the OpenThread instance.
      *
      */
-    ChannelMonitor(Instance &aInstance);
+    explicit ChannelMonitor(Instance &aInstance);
 
     /**
      * This method starts the Channel Monitoring operation.
diff --git a/src/ncp/ncp_base.hpp b/src/ncp/ncp_base.hpp
index 76f3126ad..2991147a1 100644
--- a/src/ncp/ncp_base.hpp
+++ b/src/ncp/ncp_base.hpp
@@ -68,7 +68,7 @@ public:
      * @param[in]  aInstance  The OpenThread instance structure.
      *
      */
-    NcpBase(Instance *aInstance);
+    explicit NcpBase(Instance *aInstance);
 
     /**
      * This static method returns the pointer to the single NCP instance.
diff --git a/src/ncp/ncp_spi.hpp b/src/ncp/ncp_spi.hpp
index 4d381a8db..4bcb34784 100644
--- a/src/ncp/ncp_spi.hpp
+++ b/src/ncp/ncp_spi.hpp
@@ -58,7 +58,7 @@ public:
      * @param[in] aBuffer     Pointer to buffer containing the frame.
      *
      */
-    SpiFrame(uint8_t *aBuffer)
+    explicit SpiFrame(uint8_t *aBuffer)
         : mBuffer(aBuffer)
     {
     }
@@ -152,7 +152,7 @@ public:
      * @param[in]  aInstance  A pointer to the OpenThread instance structure.
      *
      */
-    NcpSpi(Instance *aInstance);
+    explicit NcpSpi(Instance *aInstance);
 
 private:
     enum
diff --git a/src/ncp/ncp_uart.hpp b/src/ncp/ncp_uart.hpp
index a61fa5819..0a4a390df 100644
--- a/src/ncp/ncp_uart.hpp
+++ b/src/ncp/ncp_uart.hpp
@@ -56,7 +56,7 @@ public:
      * @param[in]  aInstance  The OpenThread instance structure.
      *
      */
-    NcpUart(Instance *aInstance);
+    explicit NcpUart(Instance *aInstance);
 
     /**
      * This method is called when uart tx is finished. It prepares and sends the next data chunk (if any) to uart.
diff --git a/src/ncp/spinel_encoder.hpp b/src/ncp/spinel_encoder.hpp
index dad009cbf..0a97e360f 100644
--- a/src/ncp/spinel_encoder.hpp
+++ b/src/ncp/spinel_encoder.hpp
@@ -59,7 +59,7 @@ public:
      * @param[in] aNcpBuffer   A reference to a `NcpFrameBuffer` where the frames are written.
      *
      */
-    SpinelEncoder(NcpFrameBuffer &aNcpBuffer)
+    explicit SpinelEncoder(NcpFrameBuffer &aNcpBuffer)
         : mNcpBuffer(aNcpBuffer)
         , mNumOpenStructs(0)
         , mSavedNumOpenStructs(0)