Fortran 类型构造器
示例
通过使用接口来重载类型名称，可以为派生类型创建自定义构造函数。这样，在构造该类型的对象时，可以使用不对应于组件的关键字参数。
module ball_mod
implicit none
! only export the derived type, and not any of the
! constructors themselves
private
public :: ball
type :: ball_t
real :: mass
end type ball_t
! Writing an interface overloading 'ball_t' allows us to
! overload the type constructor
interface ball_t
procedure :: new_ball
end interface ball_t
contains
type(ball_t) function new_ball(heavy)
logical, intent(in) :: heavy
if (heavy) then
new_ball%mass = 100
else
new_ball%mass = 1
end if
end function new_ball
end module ball_mod
program test
use ball_mod
implicit none
type(ball_t) :: football
type(ball_t) :: boulder
! sets football%mass to 4.5
football = ball_t(4.5)
! calls 'ball_mod::new_ball'
boulder = ball_t(heavy=.true.)
end program test与使用单独的初始化例程相比，它可以用于制作更整洁的API：
subroutine make_heavy_ball(ball) type(ball_t), intent(inout) :: ball ball%mass = 100 end subroutine make_heavy_ball ... call make_heavy_ball(boulder)