How to set up a single project
Open the project pro file and change CONFIG += console c++11 to CONFIG += console c++17.
The c++17 setup method is permanently supported by default
Find the Qt5 installation directory, my installation directory is in the D drive Qt5.12.3 folder, open the following directory: D:\Qt5.12.3\Tools\QtCreator\share\ QtCreator\ templates\wizards\projects\plaincpp, find the file file.pro, open it with notepad, Change CONFIG += console c++11 to CONFIG += console c++17, and all new projects will support c++17 by default.