Store a function address in a variable at runtime

I use the addr_ function to get the address of functions. It works except for functions with no parameters. For functions without parameters, it crashes. How can I get the address of a function with no parameters?

void TestInt(int i) { print "TestInt" }
int iTestInt = addr_(TestInt); print iTestInt // Works

void Test() { print "Test" }
// int iTest = addr_(Test); print iTest // Crashes