main.obj:-1: error: LNK2019: unresolved external symbol "public: virtual __thiscall QgsApplication::~QgsApplication(void)" (??1QgsApplication@@UAE@XZ) referenced in function _main
main.obj:-1: error: LNK2019: unresolved external symbol "public: __thiscall QgsApplication::QgsApplication(int &,char * *,bool,class QString)" (??0QgsApplication@@QAE@AAHPAPAD_NVQString@@@Z) referenced in function _main

QgsMapLayerRegistry::instance()->addMapLayer(mypLayer, TRUE);

error: LNK2019: unresolved external symbol "public: class QgsMapLayer * __thiscall QgsMapLayerRegistry::addMapLayer(class QgsMapLayer *,bool,bool)"

QgsMapLayerRegistry::instance()->addMapLayers(QList<QgsMapLayer*>() << mypLayer);

error: LNK2019: unresolved external symbol "public: class QList<class QgsMapLayer *> __thiscall QgsMapLayerRegistry::addMapLayers(class QList<class QgsMapLayer *>,bool,bool)"