• Fortran 中的指针

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• 指针可以看作一种数据类型
  • 指针存储与之关联的数据的内存地址
  • 变量指针：指向变量
  • 数组指针：指向数组
  • 过程指针：指向函数或子程序
• 指针状态
  • 未定义
  • 未关联

integer, pointer::p1=>null()
!或者
nullify(p1)

• • 已关联

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• 指针操作
  • 指向
    • 将变量、数组、过程或指针的内存地址以及其他信息（数组上下界、过程接口等）赋值给指针
  • 赋值
    • 将非过程的量所关联的值赋值到指针所关联的地址。涉及到的所有指针必须已经关联到足够的内存空间

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• 指针状态查询函数

associated(pointer) !是否已经有关联
associated(target, pointer) !这两个是否有关联

• example-1：变量指针

! A fortran95 program for G95
! By WQY
program testimplicit noneinteger, target::a=1integer, pointer::p=>null()print*, associated(p)p=>aprint*, associated(p)print*, associated(p, a)pause
end program

• example-2：数组指针

! A fortran95 program for G95
! By WQY
program testimplicit noneinteger, target::a(2, 3)=999integer, pointer::p(:, :)=>null()print*, associated(p)p=>aprint*, associated(p)print*, associated(p, a)pause
end program

• example-3:过程指针

! A fortran95 program for G95
! By WQY
program testuse minteger::a=1procedure(pro), pointer::pinterfacesubroutine pro(a)integer aend subroutineend interfacep=>subcall p(a)pause
end programmodule mcontainssubroutine sub(a)integer aprint*, "sub:", aend subroutine sub
end module

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