Binary operator functions require their arguments to have intent(in).
Gfortran currently doesn't enforce this, ifort does.
$ cat oper-fun.f90
module mymod
interface operator (.foo.)
module procedure foo_int
end interface
contains
function foo_int (a, b)
integer:: foo_int
integer :: a, b ! <==== should be intent(in) here
foo_int = a + 3 * b
end function foo_int
end module mymod
program main
use mymod
print *, 1 .foo. 2
end program main
$ gfortran oper-fun.f90 && ./a.out
7
$ ifort oper-fun.f90
fortcom: Error: oper-fun.f90, line 6: An explicit INTENT(IN) declaration is
expected for this dummy argument of the defined operation. [A]
function foo_int (a, b)
--------------------^
fortcom: Error: oper-fun.f90, line 6: An explicit INTENT(IN) declaration is
expected for this dummy argument of the defined operation. [B]
function foo_int (a, b)
-----------------------^
fortcom: Error: oper-fun.f90, line 14: Error in opening the Library module
file. [MYMOD]
use mymod
------^
fortcom: Error: oper-fun.f90, line 15: Dotted string neither a defined operator
nor a structure component [FOO]
print *, 1 .foo. 2
--------------^
compilation aborted for oper-fun.f90 (code 1)
--
Summary: binary operator functions should require intent(in)
Product: gcc
Version: 4.2.0
Status: UNCONFIRMED
Keywords: accepts-invalid, diagnostic
Severity: normal
Priority: P3
Component: fortran
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: tkoenig at gcc dot gnu dot org
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=27122
