logging.h re-enables disabled warning C4275 (MSVC)

[bjornpiltz]

The following source file

#include <QString>
#include <glog/logging.h>
#include <QException>

emits a warning, even though both Qt and glog explicitly disable that warning.

1>c:\qt\5.9.1\msvc2017_64\include\qtcore\qexception.h(60): warning C4275: non dll-interface class 'std::exception' used as base for dll-interface class 'QException'
1>C:\Program Files (x86)\Microsoft Visual Studio\2017\Community\VC\Tools\MSVC\14.11.25503\include\vcruntime_exception.h(43): note: see declaration of 'std::exception'
1>c:\qt\5.9.1\msvc2017_64\include\qtcore\qexception.h(59): note: see declaration of 'QException'

The following lines in logging.h are the culprits:

# pragma warning(disable: 4275)
  class GOOGLE_GLOG_DLL_DECL LogStream : public std::ostream {
# pragma warning(default: 4275)

They can be fixed as follows.

# pragma warning (push)
# pragma warning(disable: 4275)
  class GOOGLE_GLOG_DLL_DECL LogStream : public std::ostream {
# pragma warning (pop)

There seems to be a consensus that this is the right way to do it.