Fortran INTENT 属性，带有带向量下标的实参

Question

the document about intent attribute说

If an actual argument is an array section with a vector subscript, it cannot be associated with a dummy array that is defined or redefined (has intent OUT or INOUT).

我应该如何理解描述？

是不是说明下面的代码是错误的？

subroutine sub(a)
    real, intent(out) :: a(:)
end subroutine sub

real :: arr(3,4)
call sub(arr(1,:))

Answer 1

那很好，它是一个数组部分而不是一个向量下标。后者是您对下标使用秩为一的整数数组表达式的地方。扩展您的示例:

subroutine sub(a)
    real, intent(out) :: a(:)
end subroutine sub

real :: arr(3,4)
call sub(arr(1,:))           ! Legal
call sub(arr(1,[ 1, 2, 4 ] ) ! Illegal