server/include/util.h

/*
 * This file is part of Crossfire TRT, the Multiplayer Online Role Playing Game.
 * 
 * Copyright (©) 2005,2006,2007 Marc Alexander Lehmann / Robin Redeker / the Crossfire TRT team
 * 
 * Crossfire TRT is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the Free
 * Software Foundation; either version 2 of the License, or (at your option)
 * any later version.
 * 
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
 * for more details.
 * 
 * You should have received a copy of the GNU General Public License along
 * with Crossfire TRT; if not, write to the Free Software Foundation, Inc. 51
 * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 * 
 * The authors can be reached via e-mail to <crossfire@schmorp.de>
 */

#ifndef UTIL_H__
#define UTIL_H__

//#define PREFER_MALLOC

#if __GNUC__ >= 3
# define is_constant(c)             __builtin_constant_p (c)
# define expect(expr,value)         __builtin_expect ((expr),(value))
# define prefetch(addr,rw,locality) __builtin_prefetch (addr, rw, locality)
#else
# define is_constant(c)             0
# define expect(expr,value)         (expr)
# define prefetch(addr,rw,locality)
#endif

#if __GNUC__ < 4 || (__GNUC__ == 4 || __GNUC_MINOR__ < 4)
# define decltype(x) typeof(x)
#endif

// put into ifs if you are very sure that the expression
// is mostly true or mosty false. note that these return
// booleans, not the expression.
#define expect_false(expr) expect ((expr) != 0, 0)
#define expect_true(expr)  expect ((expr) != 0, 1)

#include <cstddef>
#include <cmath>
#include <new>
#include <vector>

#include <glib.h>

#include <shstr.h>
#include <traits.h>

// use a gcc extension for auto declarations until ISO C++ sanctifies them
#define auto(var,expr) decltype(expr) var = (expr)

// very ugly macro that basicaly declares and initialises a variable
// that is in scope for the next statement only
// works only for stuff that can be assigned 0 and converts to false
// (note: works great for pointers)
// most ugly macro I ever wrote
#define declvar(type, name, value) if (type name = 0) { } else if (((name) = (value)), 1)

// in range including end
#define IN_RANGE_INC(val,beg,end) \
  ((unsigned int)(val) - (unsigned int)(beg) <= (unsigned int)(end) - (unsigned int)(beg))

// in range excluding end
#define IN_RANGE_EXC(val,beg,end) \
  ((unsigned int)(val) - (unsigned int)(beg) <  (unsigned int)(end) - (unsigned int)(beg))

void fork_abort (const char *msg);

// rationale for using (U) not (T) is to reduce signed/unsigned issues,
// as a is often a constant while b is the variable. it is still a bug, though.
template<typename T, typename U> static inline T min (T a, U b) { return (U)a < b ? (U)a : b; }
template<typename T, typename U> static inline T max (T a, U b) { return (U)a > b ? (U)a : b; }
template<typename T, typename U, typename V> static inline T clamp (T v, U a, V b) { return v < (T)a ? (T)a : v >(T)b ? (T)b : v; }

template<typename T, typename U> static inline void swap (T& a, U& b) { T t=a; a=(T)b; b=(U)t; }

template<typename T>
static inline T
lerp (T val, T min_in, T max_in, T min_out, T max_out)
{
  return (val - min_in) * (max_out - min_out) / (max_in - min_in) + min_out;
}

// lots of stuff taken from FXT

/* Rotate right. This is used in various places for checksumming */
//TODO: that sucks, use a better checksum algo
static inline uint32_t
rotate_right (uint32_t c, uint32_t count = 1)
{
  return (c << (32 - count)) | (c >> count);
}

static inline uint32_t
rotate_left (uint32_t c, uint32_t count = 1)
{
  return (c >> (32 - count)) | (c << count);
}

// Return abs(a-b)
// Both a and b must not have the most significant bit set
static inline uint32_t
upos_abs_diff (uint32_t a, uint32_t b)
{
  long d1 = b - a;
  long d2 = (d1 & (d1 >> 31)) << 1;

  return d1 - d2;               // == (b - d) - (a + d);
}

// Both a and b must not have the most significant bit set
static inline uint32_t
upos_min (uint32_t a, uint32_t b)
{
  int32_t d = b - a;
  d &= d >> 31;
  return a + d;
}

// Both a and b must not have the most significant bit set
static inline uint32_t
upos_max (uint32_t a, uint32_t b)
{
  int32_t d = b - a;
  d &= d >> 31;
  return b - d;
}

// this is much faster than crossfires original algorithm
// on modern cpus
inline int
isqrt (int n)
{
  return (int)sqrtf ((float)n);
}

// this is only twice as fast as naive sqrtf (dx*dy+dy*dy)
#if 0
// and has a max. error of 6 in the range -100..+100.
#else
// and has a max. error of 9 in the range -100..+100.
#endif
inline int 
idistance (int dx, int dy)
{ 
  unsigned int dx_ = abs (dx);
  unsigned int dy_ = abs (dy);

#if 0
  return dx_ > dy_
      ? (dx_ * 61685 + dy_ * 26870) >> 16
      : (dy_ * 61685 + dx_ * 26870) >> 16;
#else
  return dx_ + dy_ - min (dx_, dy_) * 5 / 8;
#endif
}

/*
 * absdir(int): Returns a number between 1 and 8, which represent
 * the "absolute" direction of a number (it actually takes care of
 * "overflow" in previous calculations of a direction).
 */
inline int
absdir (int d)
{
  return ((d - 1) & 7) + 1;
}

// makes dynamically allocated objects zero-initialised
struct zero_initialised
{
  void *operator new (size_t s, void *p)
  {
    memset (p, 0, s);
    return p;
  }

  void *operator new (size_t s)
  {
    return g_slice_alloc0 (s);
  }

  void *operator new[] (size_t s)
  {
    return g_slice_alloc0 (s);
  }

  void operator delete (void *p, size_t s)
  {
    g_slice_free1 (s, p);
  }

  void operator delete[] (void *p, size_t s)
  {
    g_slice_free1 (s, p);
  }
};

void *salloc_ (int n)            throw (std::bad_alloc);
void *salloc_ (int n, void *src) throw (std::bad_alloc);

// strictly the same as g_slice_alloc, but never returns 0
template<typename T>
inline T *salloc (int n = 1)     throw (std::bad_alloc) { return (T *)salloc_ (n * sizeof (T));              }

// also copies src into the new area, like "memdup"
// if src is 0, clears the memory
template<typename T>
inline T *salloc (int n, T *src) throw (std::bad_alloc) { return (T *)salloc_ (n * sizeof (T), (void *)src); }

// clears the memory
template<typename T>
inline T *salloc0(int n = 1)     throw (std::bad_alloc) { return (T *)salloc_ (n * sizeof (T), 0);           }

// for symmetry
template<typename T>
inline void sfree (T *ptr, int n = 1) throw ()
{
#ifdef PREFER_MALLOC
  free (ptr);
#else
  g_slice_free1 (n * sizeof (T), (void *)ptr);
#endif
}

// a STL-compatible allocator that uses g_slice
// boy, this is verbose
template<typename Tp>
struct slice_allocator
{
  typedef size_t size_type;
  typedef ptrdiff_t difference_type;
  typedef Tp *pointer;
  typedef const Tp *const_pointer;
  typedef Tp &reference;
  typedef const Tp &const_reference;
  typedef Tp value_type;

  template <class U> 
  struct rebind
  {
    typedef slice_allocator<U> other;
  };

  slice_allocator () throw () { }
  slice_allocator (const slice_allocator &o) throw () { }
  template<typename Tp2>
  slice_allocator (const slice_allocator<Tp2> &) throw () { }

  ~slice_allocator () { }

  pointer address (reference x) const { return &x; }
  const_pointer address (const_reference x) const { return &x; }

  pointer allocate (size_type n, const_pointer = 0)
  {
    return salloc<Tp> (n);
  }

  void deallocate (pointer p, size_type n)
  {
    sfree<Tp> (p, n);
  }

  size_type max_size ()const throw ()
  {
    return size_t (-1) / sizeof (Tp);
  }

  void construct (pointer p, const Tp &val)
  {
    ::new (p) Tp (val);
  }

  void destroy (pointer p)
  {
    p->~Tp ();
  }
};

// P. L'Ecuyer, “Maximally Equidistributed Combined Tausworthe Generators”, Mathematics of Computation, 65, 213 (1996), 203–213.
// http://www.iro.umontreal.ca/~lecuyer/myftp/papers/tausme.ps
// http://www.iro.umontreal.ca/~lecuyer/myftp/papers/tausme2.ps
struct tausworthe_random_generator
{
  // generator
  uint32_t state [4];

  void operator =(const tausworthe_random_generator &src)
  {
    state [0] = src.state [0];
    state [1] = src.state [1];
    state [2] = src.state [2];
    state [3] = src.state [3];
  }

  void seed (uint32_t seed);
  uint32_t next ();

  // uniform distribution
  uint32_t operator ()(uint32_t num)
  {
    return is_constant (num)
             ? (next () * (uint64_t)num) >> 32U
             : get_range (num);
  }

  // return a number within (min .. max)
  int operator () (int r_min, int r_max)
  {
    return is_constant (r_min) && is_constant (r_max) && r_min <= r_max
              ? r_min + operator ()(r_max - r_min + 1)
              : get_range (r_min, r_max);
  }

  double operator ()()
  {
    return this->next () / (double)0xFFFFFFFFU;
  }

protected:
  uint32_t get_range (uint32_t r_max);
  int get_range (int r_min, int r_max);
};

typedef tausworthe_random_generator rand_gen;

extern rand_gen rndm;

template<class T>
struct refptr
{
  T *p;

  refptr () : p(0) { }
  refptr (const refptr<T> &p) : p(p.p) { if (p) p->refcnt_inc (); }
  refptr (T *p) : p(p) { if (p) p->refcnt_inc (); }
  ~refptr () { if (p) p->refcnt_dec (); }

  const refptr<T> &operator =(T *o)
  {
    if (p) p->refcnt_dec ();
    p = o;
    if (p) p->refcnt_inc ();

    return *this;
  }

  const refptr<T> &operator =(const refptr<T> o)
  {
    *this = o.p;
    return *this;
  }

  T &operator * () const { return *p; }
  T *operator ->() const { return p; }

  operator T *() const { return p; }
};

typedef refptr<maptile>   maptile_ptr;
typedef refptr<object>    object_ptr;
typedef refptr<archetype> arch_ptr;
typedef refptr<client>    client_ptr;
typedef refptr<player>    player_ptr;

struct str_hash
{
  std::size_t operator ()(const char *s) const
  {
    unsigned long hash = 0;

    /* use the one-at-a-time hash function, which supposedly is
     * better than the djb2-like one used by perl5.005, but
     * certainly is better then the bug used here before.
     * see http://burtleburtle.net/bob/hash/doobs.html
     */
    while (*s)
      {
        hash += *s++;
        hash += hash << 10;
        hash ^= hash >>  6;
      }

    hash += hash <<  3;
    hash ^= hash >> 11;
    hash += hash << 15;

    return hash;
  }
};

struct str_equal
{
  bool operator ()(const char *a, const char *b) const
  {
    return !strcmp (a, b);
  }
};

template<class T>
struct unordered_vector : std::vector<T, slice_allocator<T> >
{
  typedef typename unordered_vector::iterator iterator;

  void erase (unsigned int pos)
  {
    if (pos < this->size () - 1)
      (*this)[pos] = (*this)[this->size () - 1];

    this->pop_back ();
  }

  void erase (iterator i)
  {
    erase ((unsigned int )(i - this->begin ()));
  }
};

template<class T, int T::* index>
struct object_vector : std::vector<T *, slice_allocator<T *> >
{
  void insert (T *obj)
  {
    assert (!(obj->*index));
    push_back (obj);
    obj->*index = this->size ();
  }

  void insert (T &obj)
  {
    insert (&obj);
  }

  void erase (T *obj)
  {
    assert (obj->*index);
    unsigned int pos = obj->*index;
    obj->*index = 0;

    if (pos < this->size ())
      {
        (*this)[pos - 1] = (*this)[this->size () - 1];
        (*this)[pos - 1]->*index = pos;
      }

    this->pop_back ();
  }

  void erase (T &obj)
  {
    errase (&obj);
  }
};

// basically does what strncpy should do, but appends "..." to strings exceeding length
void assign (char *dst, const char *src, int maxlen);

// type-safe version of assign
template<int N>
inline void assign (char (&dst)[N], const char *src)
{
  assign ((char *)&dst, src, N);
}

typedef double tstamp;

// return current time as timestampe
tstamp now ();

int similar_direction (int a, int b);

// like printf, but returns a std::string
const std::string format (const char *format, ...);

#endif

Revision:	1.47
Committed:	Sat Jun 2 03:48:29 2007 UTC (16 years, 11 months ago) by root
Content type:	text/plain
Branch:	MAIN
Changes since 1.46:	+5 -1 lines
Log Message:	g++ finally got decltype
#	Content
1	/*
2	* This file is part of Crossfire TRT, the Multiplayer Online Role Playing Game.
3	*
4	* Copyright (©) 2005,2006,2007 Marc Alexander Lehmann / Robin Redeker / the Crossfire TRT team
5	*
6	* Crossfire TRT is free software; you can redistribute it and/or modify it
7	* under the terms of the GNU General Public License as published by the Free
8	* Software Foundation; either version 2 of the License, or (at your option)
9	* any later version.
10	*
11	* This program is distributed in the hope that it will be useful, but
12	* WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
13	* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14	* for more details.
15	*
16	* You should have received a copy of the GNU General Public License along
17	* with Crossfire TRT; if not, write to the Free Software Foundation, Inc. 51
18	* Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19	*
20	* The authors can be reached via e-mail to <crossfire@schmorp.de>
21	*/
22
23	#ifndef UTIL_H__
24	#define UTIL_H__
25
26	//#define PREFER_MALLOC
27
28	#if __GNUC__ >= 3
29	# define is_constant(c) __builtin_constant_p (c)
30	# define expect(expr,value) __builtin_expect ((expr),(value))
31	# define prefetch(addr,rw,locality) __builtin_prefetch (addr, rw, locality)
32	#else
33	# define is_constant(c) 0
34	# define expect(expr,value) (expr)
35	# define prefetch(addr,rw,locality)
36	#endif
37
38	#if __GNUC__ < 4 \|\| (__GNUC__ == 4 \|\| __GNUC_MINOR__ < 4)
39	# define decltype(x) typeof(x)
40	#endif
41
42	// put into ifs if you are very sure that the expression
43	// is mostly true or mosty false. note that these return
44	// booleans, not the expression.
45	#define expect_false(expr) expect ((expr) != 0, 0)
46	#define expect_true(expr) expect ((expr) != 0, 1)
47
48	#include <cstddef>
49	#include <cmath>
50	#include <new>
51	#include <vector>
52
53	#include <glib.h>
54
55	#include <shstr.h>
56	#include <traits.h>
57
58	// use a gcc extension for auto declarations until ISO C++ sanctifies them
59	#define auto(var,expr) decltype(expr) var = (expr)
60
61	// very ugly macro that basicaly declares and initialises a variable
62	// that is in scope for the next statement only
63	// works only for stuff that can be assigned 0 and converts to false
64	// (note: works great for pointers)
65	// most ugly macro I ever wrote
66	#define declvar(type, name, value) if (type name = 0) { } else if (((name) = (value)), 1)
67
68	// in range including end
69	#define IN_RANGE_INC(val,beg,end) \
70	((unsigned int)(val) - (unsigned int)(beg) <= (unsigned int)(end) - (unsigned int)(beg))
71
72	// in range excluding end
73	#define IN_RANGE_EXC(val,beg,end) \
74	((unsigned int)(val) - (unsigned int)(beg) < (unsigned int)(end) - (unsigned int)(beg))
75
76	void fork_abort (const char *msg);
77
78	// rationale for using (U) not (T) is to reduce signed/unsigned issues,
79	// as a is often a constant while b is the variable. it is still a bug, though.
80	template<typename T, typename U> static inline T min (T a, U b) { return (U)a < b ? (U)a : b; }
81	template<typename T, typename U> static inline T max (T a, U b) { return (U)a > b ? (U)a : b; }
82	template<typename T, typename U, typename V> static inline T clamp (T v, U a, V b) { return v < (T)a ? (T)a : v >(T)b ? (T)b : v; }
83
84	template<typename T, typename U> static inline void swap (T& a, U& b) { T t=a; a=(T)b; b=(U)t; }
85
86	template<typename T>
87	static inline T
88	lerp (T val, T min_in, T max_in, T min_out, T max_out)
89	{
90	return (val - min_in) * (max_out - min_out) / (max_in - min_in) + min_out;
91	}
92
93	// lots of stuff taken from FXT
94
95	/* Rotate right. This is used in various places for checksumming */
96	//TODO: that sucks, use a better checksum algo
97	static inline uint32_t
98	rotate_right (uint32_t c, uint32_t count = 1)
99	{
100	return (c << (32 - count)) \| (c >> count);
101	}
102
103	static inline uint32_t
104	rotate_left (uint32_t c, uint32_t count = 1)
105	{
106	return (c >> (32 - count)) \| (c << count);
107	}
108
109	// Return abs(a-b)
110	// Both a and b must not have the most significant bit set
111	static inline uint32_t
112	upos_abs_diff (uint32_t a, uint32_t b)
113	{
114	long d1 = b - a;
115	long d2 = (d1 & (d1 >> 31)) << 1;
116
117	return d1 - d2; // == (b - d) - (a + d);
118	}
119
120	// Both a and b must not have the most significant bit set
121	static inline uint32_t
122	upos_min (uint32_t a, uint32_t b)
123	{
124	int32_t d = b - a;
125	d &= d >> 31;
126	return a + d;
127	}
128
129	// Both a and b must not have the most significant bit set
130	static inline uint32_t
131	upos_max (uint32_t a, uint32_t b)
132	{
133	int32_t d = b - a;
134	d &= d >> 31;
135	return b - d;
136	}
137
138	// this is much faster than crossfires original algorithm
139	// on modern cpus
140	inline int
141	isqrt (int n)
142	{
143	return (int)sqrtf ((float)n);
144	}
145
146	// this is only twice as fast as naive sqrtf (dxdy+dydy)
147	#if 0
148	// and has a max. error of 6 in the range -100..+100.
149	#else
150	// and has a max. error of 9 in the range -100..+100.
151	#endif
152	inline int
153	idistance (int dx, int dy)
154	{
155	unsigned int dx_ = abs (dx);
156	unsigned int dy_ = abs (dy);
157
158	#if 0
159	return dx_ > dy_
160	? (dx_ * 61685 + dy_ * 26870) >> 16
161	: (dy_ * 61685 + dx_ * 26870) >> 16;
162	#else
163	return dx_ + dy_ - min (dx_, dy_) * 5 / 8;
164	#endif
165	}
166
167	/*
168	* absdir(int): Returns a number between 1 and 8, which represent
169	* the "absolute" direction of a number (it actually takes care of
170	* "overflow" in previous calculations of a direction).
171	*/
172	inline int
173	absdir (int d)
174	{
175	return ((d - 1) & 7) + 1;
176	}
177
178	// makes dynamically allocated objects zero-initialised
179	struct zero_initialised
180	{
181	void operator new (size_t s, void p)
182	{
183	memset (p, 0, s);
184	return p;
185	}
186
187	void *operator new (size_t s)
188	{
189	return g_slice_alloc0 (s);
190	}
191
192	void *operator new[] (size_t s)
193	{
194	return g_slice_alloc0 (s);
195	}
196
197	void operator delete (void *p, size_t s)
198	{
199	g_slice_free1 (s, p);
200	}
201
202	void operator delete[] (void *p, size_t s)
203	{
204	g_slice_free1 (s, p);
205	}
206	};
207
208	void *salloc_ (int n) throw (std::bad_alloc);
209	void salloc_ (int n, void src) throw (std::bad_alloc);
210
211	// strictly the same as g_slice_alloc, but never returns 0
212	template<typename T>
213	inline T salloc (int n = 1) throw (std::bad_alloc) { return (T )salloc_ (n * sizeof (T)); }
214
215	// also copies src into the new area, like "memdup"
216	// if src is 0, clears the memory
217	template<typename T>
218	inline T salloc (int n, T src) throw (std::bad_alloc) { return (T )salloc_ (n sizeof (T), (void *)src); }
219
220	// clears the memory
221	template<typename T>
222	inline T salloc0(int n = 1) throw (std::bad_alloc) { return (T )salloc_ (n * sizeof (T), 0); }
223
224	// for symmetry
225	template<typename T>
226	inline void sfree (T *ptr, int n = 1) throw ()
227	{
228	#ifdef PREFER_MALLOC
229	free (ptr);
230	#else
231	g_slice_free1 (n * sizeof (T), (void *)ptr);
232	#endif
233	}
234
235	// a STL-compatible allocator that uses g_slice
236	// boy, this is verbose
237	template<typename Tp>
238	struct slice_allocator
239	{
240	typedef size_t size_type;
241	typedef ptrdiff_t difference_type;
242	typedef Tp *pointer;
243	typedef const Tp *const_pointer;
244	typedef Tp &reference;
245	typedef const Tp &const_reference;
246	typedef Tp value_type;
247
248	template <class U>
249	struct rebind
250	{
251	typedef slice_allocator<U> other;
252	};
253
254	slice_allocator () throw () { }
255	slice_allocator (const slice_allocator &o) throw () { }
256	template<typename Tp2>
257	slice_allocator (const slice_allocator<Tp2> &) throw () { }
258
259	~slice_allocator () { }
260
261	pointer address (reference x) const { return &x; }
262	const_pointer address (const_reference x) const { return &x; }
263
264	pointer allocate (size_type n, const_pointer = 0)
265	{
266	return salloc<Tp> (n);
267	}
268
269	void deallocate (pointer p, size_type n)
270	{
271	sfree<Tp> (p, n);
272	}
273
274	size_type max_size ()const throw ()
275	{
276	return size_t (-1) / sizeof (Tp);
277	}
278
279	void construct (pointer p, const Tp &val)
280	{
281	::new (p) Tp (val);
282	}
283
284	void destroy (pointer p)
285	{
286	p->~Tp ();
287	}
288	};
289
290	// P. L'Ecuyer, “Maximally Equidistributed Combined Tausworthe Generators”, Mathematics of Computation, 65, 213 (1996), 203–213.
291	// http://www.iro.umontreal.ca/~lecuyer/myftp/papers/tausme.ps
292	// http://www.iro.umontreal.ca/~lecuyer/myftp/papers/tausme2.ps
293	struct tausworthe_random_generator
294	{
295	// generator
296	uint32_t state [4];
297
298	void operator =(const tausworthe_random_generator &src)
299	{
300	state [0] = src.state [0];
301	state [1] = src.state [1];
302	state [2] = src.state [2];
303	state [3] = src.state [3];
304	}
305
306	void seed (uint32_t seed);
307	uint32_t next ();
308
309	// uniform distribution
310	uint32_t operator ()(uint32_t num)
311	{
312	return is_constant (num)
313	? (next () * (uint64_t)num) >> 32U
314	: get_range (num);
315	}
316
317	// return a number within (min .. max)
318	int operator () (int r_min, int r_max)
319	{
320	return is_constant (r_min) && is_constant (r_max) && r_min <= r_max
321	? r_min + operator ()(r_max - r_min + 1)
322	: get_range (r_min, r_max);
323	}
324
325	double operator ()()
326	{
327	return this->next () / (double)0xFFFFFFFFU;
328	}
329
330	protected:
331	uint32_t get_range (uint32_t r_max);
332	int get_range (int r_min, int r_max);
333	};
334
335	typedef tausworthe_random_generator rand_gen;
336
337	extern rand_gen rndm;
338
339	template<class T>
340	struct refptr
341	{
342	T *p;
343
344	refptr () : p(0) { }
345	refptr (const refptr<T> &p) : p(p.p) { if (p) p->refcnt_inc (); }
346	refptr (T *p) : p(p) { if (p) p->refcnt_inc (); }
347	~refptr () { if (p) p->refcnt_dec (); }
348
349	const refptr<T> &operator =(T *o)
350	{
351	if (p) p->refcnt_dec ();
352	p = o;
353	if (p) p->refcnt_inc ();
354
355	return *this;
356	}
357
358	const refptr<T> &operator =(const refptr<T> o)
359	{
360	*this = o.p;
361	return *this;
362	}
363
364	T &operator * () const { return *p; }
365	T *operator ->() const { return p; }
366
367	operator T *() const { return p; }
368	};
369
370	typedef refptr<maptile> maptile_ptr;
371	typedef refptr<object> object_ptr;
372	typedef refptr<archetype> arch_ptr;
373	typedef refptr<client> client_ptr;
374	typedef refptr<player> player_ptr;
375
376	struct str_hash
377	{
378	std::size_t operator ()(const char *s) const
379	{
380	unsigned long hash = 0;
381
382	/* use the one-at-a-time hash function, which supposedly is
383	* better than the djb2-like one used by perl5.005, but
384	* certainly is better then the bug used here before.
385	* see http://burtleburtle.net/bob/hash/doobs.html
386	*/
387	while (*s)
388	{
389	hash += *s++;
390	hash += hash << 10;
391	hash ^= hash >> 6;
392	}
393
394	hash += hash << 3;
395	hash ^= hash >> 11;
396	hash += hash << 15;
397
398	return hash;
399	}
400	};
401
402	struct str_equal
403	{
404	bool operator ()(const char a, const char b) const
405	{
406	return !strcmp (a, b);
407	}
408	};
409
410	template<class T>
411	struct unordered_vector : std::vector<T, slice_allocator<T> >
412	{
413	typedef typename unordered_vector::iterator iterator;
414
415	void erase (unsigned int pos)
416	{
417	if (pos < this->size () - 1)
418	(this)[pos] = (this)[this->size () - 1];
419
420	this->pop_back ();
421	}
422
423	void erase (iterator i)
424	{
425	erase ((unsigned int )(i - this->begin ()));
426	}
427	};
428
429	template<class T, int T::* index>
430	struct object_vector : std::vector<T , slice_allocator<T > >
431	{
432	void insert (T *obj)
433	{
434	assert (!(obj->*index));
435	push_back (obj);
436	obj->*index = this->size ();
437	}
438
439	void insert (T &obj)
440	{
441	insert (&obj);
442	}
443
444	void erase (T *obj)
445	{
446	assert (obj->*index);
447	unsigned int pos = obj->*index;
448	obj->*index = 0;
449
450	if (pos < this->size ())
451	{
452	(this)[pos - 1] = (this)[this->size () - 1];
453	(this)[pos - 1]->index = pos;
454	}
455
456	this->pop_back ();
457	}
458
459	void erase (T &obj)
460	{
461	errase (&obj);
462	}
463	};
464
465	// basically does what strncpy should do, but appends "..." to strings exceeding length
466	void assign (char dst, const char src, int maxlen);
467
468	// type-safe version of assign
469	template<int N>
470	inline void assign (char (&dst)[N], const char *src)
471	{
472	assign ((char *)&dst, src, N);
473	}
474
475	typedef double tstamp;
476
477	// return current time as timestampe
478	tstamp now ();
479
480	int similar_direction (int a, int b);
481
482	// like printf, but returns a std::string
483	const std::string format (const char *format, ...);
484
485	#endif
486