小编Oba*_*bay的帖子

在Windows上使用cygwin64,该程序将无法编译:

program test
  implicit none

  !define my type
  type myType
    real::foo
    integer::bar
  end type myType

  !define an operator for this type
  interface operator (>)
      logical function compare(a,b)
        type(myType),intent(in) :: a,b
        compare = a%foo>b%foo
      end function compare
  end interface operator (>)

  !simple example of operator usage
  type(myType) :: tfoo, tbar
  tfoo = card(1.,2); tbar = card(3.,4)
  print*, tfoo>tbar
end program test

gfortran (只有参数是"std = f2008")告诉我:

type(myType),intent(in) :: a,b
                    1
Error: Derived type ‘mytype’ at (1) is being used before it is …

给定一个不可复制/可移动的 struct U，该结构的成员不能在构造函数中分配（请参阅C）。它们只能通过成员初始值设定项列表来初始化（请参阅 参考资料S）。

struct U {
    U(int x);
    U(U &other) = delete;
    U(U &&other) = delete;
};

struct S {
    S(int x) : u(x) {}
    U u;
};

struct C {
    C(int x) { u = U(x); }  // compiler complains: cannot assign
    U u;
};

错误：

<source>:13:5: error: constructor for 'C' must explicitly initialize the member 'u' which does not have a default constructor
    C(int x) { u = U(x); }
    ^
<source>:14:7: …