[CMake] Changing the the current generator in CMake GUI

[Greg Marr]

Bill Hoffman wrote:
	You can do it by changing the CMakeCache.txt file, but it won't work in 
the general case.  You should put them in separate directories: build-32 
and build-64.

	You can build both 32 and 64 from the same SOURCE tree, just not the 
same build tree.

	build32   (cmake ../src -G"Visual Studio 10 2010")
	build64   (cmake ../src -G"Visual Studio 10 2010 Win64")

	You seem to be trying to reuse the same build tree for different builds 
which is not a supported use case.  I think if you stopped doing that 
your life might get easier when working with CMake projects.


You can do both in the same solution/projects with the Microsoft fork of CMake, but it's not a general solution, and it doesn't handle different settings for 32 bit and 64 bit.  Because of that, they're "not pushing too hard" for it to be in mainline CMake.

https://cmake.org/pipermail/cmake/2015-August/061346.html