if(qt4){LIBS += using_json_spirit_libs}elseif(qt5){LIBS += using_native_libs}
greaterThan(QT_MAJOR_VERSION, 4) {...} else {...}
greaterThan(QT_MAJOR_VERSION, 4): IS_QT5 = 1...isEmpty(IS_QT5) {# Qt 4}else {# Qt 5}
QT += xml network guigreaterThan(QT_MAJOR_VERSION, 4){ QT += widgets multimedia}lessThan(QT_MAJOR_VERSION, 5):QT += phononunix {greaterThan(QT_MAJOR_VERSION, 4): LIBS += -L$$PWD/../../../build/libs/railcore/debug/ -lrailcore_oldlessThan(QT_MAJOR_VERSION, 5): LIBS += -L$$PWD/../../../build/libs/railcore/debug/ -lrailcore_old \ -L$$PWD/../../../build/libs/railcore/release/ -lrailcore_old \ -L/usr/local/lib \ -ljson_spirit \ -lboost_thread}
greaterThan(QT_MAJOR_VERSION, 4): { # Qt 5} else: { # Qt 4}
# Если сборка идет в Qt5 и сборка с GUI добавить модуль widgetsgreaterThan(QT_MAJOR_VERSION, 4): contains( QT, gui ): QT += widgets