How do I tell cmake not to create a console window?

Question

I can achieve this by gcc :

gcc -mwindows -o simple simple.c

But only find this in cmake:

add_executable(simple WIN32 simple.c)

But it's not exactly the same as -mwindows,

this will require the entry point to be WinMain,

while gcc -mwindows doesn't require this(can be main).

How should I do it properly?