Please use proper code formatting for easier reading (put three ` symbols before and after code).
The error is in your Window constructor - you are not initializing corwidth/corheight/cortitle members of object. Instead you are overwriting widht/height/title arguments with uninitialized values from this object. cortitle happens to be NULL, that’s why you are hitting the assert when passing it to glfwCreateWindow function.
In this kind of situation you should really use a debugger. Run program in a debugger, and when code will assert the debugger will stop. And you will be able to examine call stack. In your case you would see that the function Window::init called glfwCreateWindow which asserted. Then you would be able to examine variable values - like corwidth, cortitle - then you would immediately see where is the error.