Lot of warnings

Lot of warnings when compiling a project using Qt 5.5.1 and warnings level 4.
Here a list of warnings I have when compiling in release mode :
C:\Qt\Qt5.5.1\5.5\msvc2013_64\include\QtCore/qmutex.h(63): warning C4127: conditional expression is constant
C:\Qt\Qt5.5.1\5.5\msvc2013_64\include\QtCore/qmutex.h(123): warning C4127: conditional expression is constant
C:\Qt\Qt5.5.1\5.5\msvc2013_64\include\QtCore/qrefcount.h(73): warning C4127: conditional expression is constant
C:\Qt\Qt5.5.1\5.5\msvc2013_64\include\QtCore/qarraydata.h(53): warning C4127: conditional expression is constant
C:\Qt\Qt5.5.1\5.5\msvc2013_64\include\QtCore/qarraydata.h(60): warning C4127: conditional expression is constant
C:\Qt\Qt5.5.1\5.5\msvc2013_64\include\QtCore/qbytearray.h(464): warning C4127: conditional expression is constant
C:\Qt\Qt5.5.1\5.5\msvc2013_64\include\QtCore/qbytearray.h(466): warning C4127: conditional expression is constant
C:\Qt\Qt5.5.1\5.5\msvc2013_64\include\QtCore/qbytearray.h(468): warning C4127: conditional expression is constant
C:\Qt\Qt5.5.1\5.5\msvc2013_64\include\QtCore/qbytearray.h(546): warning C4127: conditional expression is constant
C:\Qt\Qt5.5.1\5.5\msvc2013_64\include\QtCore/qstring.h(851): warning C4127: conditional expression is constant
C:\Qt\Qt5.5.1\5.5\msvc2013_64\include\QtCore/qstring.h(853): warning C4127: conditional expression is constant
C:\Qt\Qt5.5.1\5.5\msvc2013_64\include\QtCore/qstring.h(855): warning C4127: conditional expression is constant
C:\Qt\Qt5.5.1\5.5\msvc2013_64\include\QtCore/qstring.h(878): warning C4127: conditional expression is constant
C:\Qt\Qt5.5.1\5.5\msvc2013_64\include\QtCore/qstring.h(1081): warning C4127: conditional expression is constant
C:\Qt\Qt5.5.1\5.5\msvc2013_64\include\QtCore/qstring.h(1436): warning C4127: conditional expression is constant
C:\Qt\Qt5.5.1\5.5\msvc2013_64\include\QtCore/qstring.h(1436): warning C4127: conditional expression is constant
C:\Qt\Qt5.5.1\5.5\msvc2013_64\include\QtCore/qmetatype.h(1050): warning C4127: conditional expression is constant
C:\Qt\Qt5.5.1\5.5\msvc2013_64\include\QtCore/qmetatype.h(1060): warning C4127: conditional expression is constant
C:\Qt\Qt5.5.1\5.5\msvc2013_64\include\QtCore/qmetatype.h(1229): warning C4127: conditional expression is constant
C:\Qt\Qt5.5.1\5.5\msvc2013_64\include\QtCore/qmetatype.h(1664): warning C4127: conditional expression is constant
C:\Qt\Qt5.5.1\5.5\msvc2013_64\include\QtCore/qmetatype.h(2068): warning C4127: conditional expression is constant
C:\Qt\Qt5.5.1\5.5\msvc2013_64\include\QtCore/qsize.h(175): warning C4127: conditional expression is constant
C:\Qt\Qt5.5.1\5.5\msvc2013_64\include\QtCore/qsize.h(182): warning C4127: conditional expression is constant
C:\Qt\Qt5.5.1\5.5\msvc2013_64\include\QtCore/qsize.h(340): warning C4127: conditional expression is constant
C:\Qt\Qt5.5.1\5.5\msvc2013_64\include\QtCore/qsize.h(347): warning C4127: conditional expression is constant
C:\Qt\Qt5.5.1\5.5\msvc2013_64\include\QtGui/qvector2d.h(148): warning C4127: conditional expression is constant
C:\Qt\Qt5.5.1\5.5\msvc2013_64\include\QtGui/qvector2d.h(154): warning C4127: conditional expression is constant
C:\Qt\Qt5.5.1\5.5\msvc2013_64\include\QtCore/qsharedpointer_impl.h(149): warning C4127: conditional expression is constant
C:\Qt\Qt5.5.1\5.5\msvc2013_64\include\QtCore/qscopedpointer.h(112): warning C4127: conditional expression is constant
C:\Qt\Qt5.5.1\5.5\msvc2013_64\include\QtCore/qvector.h(205): warning C4127: conditional expression is constant
C:\Qt\Qt5.5.1\5.5\msvc2013_64\include\QtCore/qvector.h(207): warning C4127: conditional expression is constant