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在Fortran中从父类继承赋值

assignment-operator fortran oop

Flo Ragossnig · 技术社区 · 6 年前

对不起,又是我!

尽管我在Fortran中的OOP越来越好(这可能是我用过的最疯狂的东西),但我在继承方面有困难。不幸的是,我不理解允许我这么做的语法。

基本上,我要做的是重写赋值运算符 = 这让我可以归还任何 . 只有一个基元类型的基本示例 (真实的) 看起来像这样:

module overload

    implicit none

    public func, assignment(=)

    interface assignment(=)
        module procedure equalAssignmentReal
        !! additional procedures for integer, character, logical if neccessary
    end interface

contains

    subroutine equalAssignmentReal(lhs, rhs)      !! <-- all these subroutines should be in the parent class

        implicit none

        real,     intent(out) :: lhs
        class(*), intent(in)  :: rhs

        select type(rhs)
            type is (real)
                lhs = rhs
        end select

        return

    end subroutine equalAssignmentReal

    function func(string) result(res)      !! <-- I want this function in the child class

        implicit none

        character(len=*), intent(in) :: string
        class(*), allocatable        :: res

        if (  string == "real" ) allocate(res, source=1.0)

        return

    end function func

end module overload

program test

    use overload

    implicit none

    real :: var

    var = func('real')

    print *, "var = ", var

end program test

这在使用编译时有效 GNU Fortran语言 (不适用于Intel,因为它们允许内部赋值重载)。所以我现在的问题是,我该如何定义父类在包含所有赋值重载(实数、整数、字符、逻辑)的单独模块中,并在只包含 func

type(child_class) :: child
real :: var

var = child%func('real')

感谢您的帮助!

1 回复 | 直到 6 年前

Flo Ragossnig 6 年前

因为似乎没有人知道答案,我也不知道如何解决这个问题类型我把这个“解决方法”贴在这里,以防有人有同样的问题。我只是把作业重载放到一个单独的模块中使用

module overload

    implicit none

    public assignment(=)

    interface assignment(=)
        module procedure equalAssignmentReal
        module procedure equalAssignmentInteger
        !! additional procedures for character, logical if neccessary
    end interface

contains

    subroutine equalAssignmentReal(lhs, rhs)

        implicit none

        real,     intent(out) :: lhs
        class(*), intent(in)  :: rhs

        select type(rhs)
            type is (real)
                lhs = rhs
        end select

        return

    end subroutine equalAssignmentReal

    subroutine equalAssignmentInteger(lhs, rhs)

        implicit none

        integer,  intent(out) :: lhs
        class(*), intent(in)  :: rhs

        select type(rhs)
            type is (integer)
                lhs = rhs
        end select

        return

    end subroutine equalAssignmentInteger

end module overload


module assignment

    implicit none

    public find
    public par1

    real    :: par1
    integer :: par2

contains

    subroutine init

        use overload

        implicit none


        par1 = find('real')
        par2 = find('integer')        

        return

    end subroutine init

    function find(in) result(out)

        implicit none

        character(len=*), intent(in)  :: in
        class(*), allocatable         :: out

        if ( in == 'real' ) then

            allocate(out, source=1.)

        else if ( in == 'integer' ) then

            allocate(out, source=2)

        end if 

        return

    end function find

end module assignment

program test

    use assignment

    implicit none

    call init

    print *, "par1 = ", par1
    print *, "par2 = ", par2

end program test