Q:

How to change all projects in a solution file to C++17 MSVC? 

I am using VS2017 (Version 15.9.12) and generated a solution file with CMake 3.14 for the VS compiler Visual Studio 15 2017. 
I want to use some C++17 features.  When I have a look in the property page of a project the field C/C++->Language->C++ Language Standard is empty.  There I can change it to /std:c++17 (and some other options). 
Since the code is an external project I do not want to change the CMake file to add CXX_Standard 17. 
Does visual studio set a compiler with C++17 option for a whole project or do I have to change this for each subprojects manually? 

A:

Looks like you have to change this for each subproject.   Alternatively just run cmake -DCMAKE_CXX_STANDARD=17 -S /path/to/external/project -B bld (for example) and CMake will generate the projects with the desired standard (unless overridden by CMakeLists.txt).