static if(!(is(FnN == TnN)))
static if(!(is(FnN == struct) && is(TnN == struct)))
static if(!(isSomeString!FnN && isSomeString!TnN))
static if(!(isArray!FnN && isArray!TnN))
static if((isIntegral!FnN || isFloatingPoint!FnN) || (isIntegral!TnN || isFloatingPoint!TnN))