Merge pull request #5419 from jhlegarreta/FixPtrConstantWarning

COMP: Use value initialization to zero-initialize thread id variable

Author: jhlegarreta

Modules/Core/Common/include/itkThreadSupport.h

@@ -42,7 +42,7 @@ using FastMutexType = pthread_mutex_t;
 using ThreadFunctionType = void * (*)(void *);
 using ThreadProcessIdType = pthread_t;
 #  if !defined(ITK_FUTURE_LEGACY_REMOVE)
-constexpr ThreadProcessIdType ITK_DEFAULT_THREAD_ID = 0;
+constexpr ThreadProcessIdType ITK_DEFAULT_THREAD_ID = {};
 #  endif
 using ITK_THREAD_RETURN_TYPE = void *;
 /** @ITKEndGrouping */

Modules/Core/Common/src/itkPlatformMultiThreaderPosix.cxx

@@ -169,7 +169,7 @@ ThreadProcessIdType
 PlatformMultiThreader::SpawnDispatchSingleMethodThread(PlatformMultiThreader::WorkUnitInfo * threadInfo)
 {
   // Using POSIX threads
-  pthread_t threadHandle = 0;
+  pthread_t threadHandle = {};
   const int threadError = pthread_create(&threadHandle,
                                          nullptr,
                                          reinterpret_cast<c_void_cast>(this->SingleMethodProxy),