Replaced boost::thread with std::thread

code/DefaultLogger.cpp

@@ -57,10 +57,10 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 #include <stdio.h>
 
 #ifndef ASSIMP_BUILD_SINGLETHREADED
-#   include <boost/thread/thread.hpp>
-#   include <boost/thread/mutex.hpp>
+#   include <thread>
+#   include <mutex>
 
-boost::mutex loggerMutex;
+std::mutex loggerMutex;
 #endif
 
 namespace Assimp    {
@@ -135,7 +135,7 @@ Logger *DefaultLogger::create(const char* name /*= "AssimpLog.txt"*/,
 {
     // enter the mutex here to avoid concurrency problems
 #ifndef ASSIMP_BUILD_SINGLETHREADED
-    boost::mutex::scoped_lock lock(loggerMutex);
+    std::lock_guard<std::mutex> lock(loggerMutex);
 #endif
 
     if (m_pLogger && !isNullLogger() )
@@ -210,7 +210,7 @@ void DefaultLogger::set( Logger *logger )
 {
     // enter the mutex here to avoid concurrency problems
 #ifndef ASSIMP_BUILD_SINGLETHREADED
-    boost::mutex::scoped_lock lock(loggerMutex);
+    std::lock_guard<std::mutex> lock(loggerMutex);
 #endif
 
     if (!logger)logger = &s_pNullLogger;
@@ -237,7 +237,7 @@ void DefaultLogger::kill()
 {
     // enter the mutex here to avoid concurrency problems
 #ifndef ASSIMP_BUILD_SINGLETHREADED
-    boost::mutex::scoped_lock lock(loggerMutex);
+    std::lock_guard<std::mutex> lock(loggerMutex);
 #endif
 
 	if ( m_pLogger == &s_pNullLogger ) {
@@ -413,7 +413,8 @@ void DefaultLogger::WriteToStreams(const char *message, ErrorSeverity ErrorSev )
 //  Returns thread id, if not supported only a zero will be returned.
 unsigned int DefaultLogger::GetThreadID()
 {
-    // fixme: we can get this value via boost::threads
+    // fixme: we can get this value via std::threads
+    // std::this_thread::get_id().hash() returns a (big) size_t, not sure if this is useful in this case.
 #ifdef WIN32
     return (unsigned int)::GetCurrentThreadId();
 #else