dr195.c

来自「Mac OS X 10.4.9 for x86 Source Code gcc」· C语言 代码 · 共 32 行

// Copyright (C) 2004 Free Software Foundation, Inc.
// Contributed by Nathan Sidwell 20 Oct 2004 <[e-mail]>

// DR 195 will allow conversions between function and object pointers
// under some circumstances. It is in drafting, so we don't implement
// it (yet).

// This checks we warn when being pedantic.

typedef void (*PF)(void);
typedef void *PV;
typedef int *PO;

void foo ()
{
  PF pf;
  PV pv;
  PO po;

  /* the following two will almost definitly be ok with 195.  */
  pf = reinterpret_cast <PF>(pv); // { dg-warning "casting between" "" }
  pv = reinterpret_cast <PV>(pf); // { dg-warning "casting between" "" }

  /* the following two might or might not be ok with 195.  */
  pf = reinterpret_cast <PF>(po); // { dg-error "casting between" "" }
  po = reinterpret_cast <PO>(pf); // { dg-error "casting between" "" }

  /* These will never be ok, as they are implicit.  */
  pv = pf; // { dg-error "invalid conversion" "" }
  pf = pv; // { dg-error "invalid conversion" "" }
}