1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
|
module operator_overloading_17_mod
type, abstract :: base
contains
procedure(if_equal), deferred :: is_equal
generic :: operator(==) => is_equal
end type base
abstract interface
logical function if_equal(lhs, rhs)
import base
class(base), intent(in) :: lhs, rhs
end function if_equal
end interface
type, extends(base) :: container
integer :: x
contains
procedure :: is_equal => container_equal
end type container
type, public :: string_t
character(len=:), allocatable :: str
end type string_t
interface operator(==)
module procedure string_equal
module procedure string_array_equal
end interface operator(==)
! type :: derived_1
! type(string_t), allocatable :: link(:)
! end type derived_1
contains
logical function container_equal(lhs, rhs)
class(base), intent(in) :: rhs
class(container), intent(in) :: lhs
container_equal = .false.
select type(rhs)
type is(container)
container_equal = rhs%x == lhs%x
end select
end function container_equal
logical function string_equal(a, b)
type(string_t), allocatable, intent(in) :: a, b
if (.not. allocated(a) .or. .not. allocated(b)) then
string_equal = .false.
return
end if
string_equal = (a%str == b%str)
end function string_equal
logical function string_array_equal(a, b)
type(string_t), intent(in) :: a(:), b(:)
integer :: i
if (size(a) /= size(b)) then
string_array_equal = .false.
return
end if
string_array_equal = .true.
do i = 1, size(a)
if (a(i)%str /= b(i)%str) then
string_array_equal = .false.
return
end if
end do
end function
end module operator_overloading_17_mod
program operator_overloading_17
use operator_overloading_17_mod
type(string_t), allocatable :: a(:), other(:)
type(string_t), allocatable :: x, y
type(container) :: c1, c2
allocate(a(2), other(2))
a(1)%str = "hello"
a(2)%str = "world"
other(1)%str = "hello"
other(2)%str = "world"
if (.not. other == a) error stop
allocate(x, y)
x%str = "hello"
y%str = "HelloWorld"
if (x == y) error stop
c1%x = 5
c2%x = 5
if (.not. c1 == c2) error stop
c2%x = 6
if (c1 == c2) error stop
associate(temp => a)
if (.not. temp == other) error stop
end associate
end program operator_overloading_17
|
