static if(is(typeof(&T) : R function(ref X, RCIAllocator = theAllocator), X, R) || is(typeof(&T) : R delegate(ref X, RCIAllocator = theAllocator), X, R) || is(typeof(T) : R function(ref X, RCIAllocator = theAllocator), X, R) || is(typeof(T) : R delegate(ref X, RCIAllocator = theAllocator), X, R))