Pointer Valued Functions

F90 allows functions to be pointer-valued. For example,

function largest(a,b)  
implicit none 
integer,target,intent(in) :: a,b 
integer,pointer :: largest 
if (a.gt.b) then 
 largest  => a 
else
 largest  => b 
end if 
end function largest

Using the generalized pointer assignment form

pointer => ptr_expression

(ptr_expression returns a pointer result), the function name must identify a target by being the LHS of a pointer assignment

integer, pointer :: greater 
greater => largest(a,b)

The interface of an external pointer valued function must always be explicit.