server/include/util.h

#ifndef UTIL_H__
#define UTIL_H__

//#define PREFER_MALLOC

#if __GNUC__ >= 3
# define is_constant(c) __builtin_constant_p (c)
#else
# define is_constant(c) 0
#endif

#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 AUTODECL(var,expr) typeof(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; }

// 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 r_max)
  {
    return is_constant (r_max)
             ? this->next () % r_max
             : get_range (r_max);
  }

  // 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 + (*this) (max (r_max - r_min + 1, 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);
    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);

#endif

Revision:	1.38
Committed:	Thu Feb 15 18:09:34 2007 UTC (17 years, 3 months ago) by root
Content type:	text/plain
Branch:	MAIN
Changes since 1.37:	+9 -3 lines
Log Message:	- the damn rotate shift checksum just failed on me - add crc32 and use it for bmaps_checksum (probably also for images).
#	User	Rev	Content
1	root	1.1	#ifndef UTIL_H__
2			#define UTIL_H__
3
4	root	1.36	//#define PREFER_MALLOC
5
6	root	1.2	#if __GNUC__ >= 3
7			# define is_constant(c) __builtin_constant_p (c)
8			#else
9			# define is_constant(c) 0
10			#endif
11
12	root	1.11	#include <cstddef>
13	root	1.28	#include <cmath>
14	root	1.25	#include <new>
15			#include <vector>
16	root	1.11
17			#include <glib.h>
18
19	root	1.25	#include <shstr.h>
20			#include <traits.h>
21
22	root	1.14	// use a gcc extension for auto declarations until ISO C++ sanctifies them
23			#define AUTODECL(var,expr) typeof(expr) var = (expr)
24
25	root	1.26	// very ugly macro that basicaly declares and initialises a variable
26			// that is in scope for the next statement only
27			// works only for stuff that can be assigned 0 and converts to false
28			// (note: works great for pointers)
29			// most ugly macro I ever wrote
30			#define declvar(type, name, value) if (type name = 0) { } else if (((name) = (value)), 1)
31
32	root	1.27	// in range including end
33			#define IN_RANGE_INC(val,beg,end) \
34			((unsigned int)(val) - (unsigned int)(beg) <= (unsigned int)(end) - (unsigned int)(beg))
35
36			// in range excluding end
37			#define IN_RANGE_EXC(val,beg,end) \
38			((unsigned int)(val) - (unsigned int)(beg) < (unsigned int)(end) - (unsigned int)(beg))
39
40	root	1.31	void fork_abort (const char *msg);
41
42	root	1.35	// rationale for using (U) not (T) is to reduce signed/unsigned issues,
43			// as a is often a constant while b is the variable. it is still a bug, though.
44			template<typename T, typename U> static inline T min (T a, U b) { return (U)a < b ? (U)a : b; }
45			template<typename T, typename U> static inline T max (T a, U b) { return (U)a > b ? (U)a : b; }
46			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; }
47	root	1.32
48			template<typename T, typename U> static inline void swap (T& a, U& b) { T t=a; a=(T)b; b=(U)t; }
49
50	root	1.37	// lots of stuff taken from FXT
51
52			/* Rotate right. This is used in various places for checksumming */
53	root	1.38	//TODO: that sucks, use a better checksum algo
54	root	1.37	static inline uint32_t
55	root	1.38	rotate_right (uint32_t c, uint32_t count = 1)
56	root	1.37	{
57	root	1.38	return (c << (32 - count)) \| (c >> count);
58			}
59
60			static inline uint32_t
61			rotate_left (uint32_t c, uint32_t count = 1)
62			{
63			return (c >> (32 - count)) \| (c << count);
64	root	1.37	}
65
66			// Return abs(a-b)
67			// Both a and b must not have the most significant bit set
68			static inline uint32_t
69			upos_abs_diff (uint32_t a, uint32_t b)
70			{
71			long d1 = b - a;
72			long d2 = (d1 & (d1 >> 31)) << 1;
73
74			return d1 - d2; // == (b - d) - (a + d);
75			}
76
77			// Both a and b must not have the most significant bit set
78			static inline uint32_t
79			upos_min (uint32_t a, uint32_t b)
80			{
81			int32_t d = b - a;
82			d &= d >> 31;
83			return a + d;
84			}
85
86			// Both a and b must not have the most significant bit set
87			static inline uint32_t
88			upos_max (uint32_t a, uint32_t b)
89			{
90			int32_t d = b - a;
91			d &= d >> 31;
92			return b - d;
93			}
94
95	root	1.28	// this is much faster than crossfires original algorithm
96			// on modern cpus
97			inline int
98			isqrt (int n)
99			{
100			return (int)sqrtf ((float)n);
101			}
102
103			// this is only twice as fast as naive sqrtf (dxdy+dydy)
104			#if 0
105			// and has a max. error of 6 in the range -100..+100.
106			#else
107			// and has a max. error of 9 in the range -100..+100.
108			#endif
109			inline int
110			idistance (int dx, int dy)
111			{
112			unsigned int dx_ = abs (dx);
113			unsigned int dy_ = abs (dy);
114
115			#if 0
116			return dx_ > dy_
117			? (dx_ * 61685 + dy_ * 26870) >> 16
118			: (dy_ * 61685 + dx_ * 26870) >> 16;
119			#else
120	root	1.30	return dx_ + dy_ - min (dx_, dy_) * 5 / 8;
121	root	1.28	#endif
122			}
123
124	root	1.29	/*
125			* absdir(int): Returns a number between 1 and 8, which represent
126			* the "absolute" direction of a number (it actually takes care of
127			* "overflow" in previous calculations of a direction).
128			*/
129			inline int
130			absdir (int d)
131			{
132			return ((d - 1) & 7) + 1;
133			}
134	root	1.28
135	root	1.1	// makes dynamically allocated objects zero-initialised
136			struct zero_initialised
137			{
138	root	1.11	void operator new (size_t s, void p)
139			{
140			memset (p, 0, s);
141			return p;
142			}
143
144			void *operator new (size_t s)
145			{
146			return g_slice_alloc0 (s);
147			}
148
149			void *operator new[] (size_t s)
150			{
151			return g_slice_alloc0 (s);
152			}
153
154			void operator delete (void *p, size_t s)
155			{
156			g_slice_free1 (s, p);
157			}
158
159			void operator delete[] (void *p, size_t s)
160			{
161			g_slice_free1 (s, p);
162			}
163			};
164
165	root	1.20	void *salloc_ (int n) throw (std::bad_alloc);
166			void salloc_ (int n, void src) throw (std::bad_alloc);
167
168	root	1.12	// strictly the same as g_slice_alloc, but never returns 0
169	root	1.20	template<typename T>
170			inline T salloc (int n = 1) throw (std::bad_alloc) { return (T )salloc_ (n * sizeof (T)); }
171
172	root	1.17	// also copies src into the new area, like "memdup"
173	root	1.18	// if src is 0, clears the memory
174			template<typename T>
175	root	1.20	inline T salloc (int n, T src) throw (std::bad_alloc) { return (T )salloc_ (n sizeof (T), (void *)src); }
176	root	1.18
177	root	1.21	// clears the memory
178			template<typename T>
179			inline T salloc0(int n = 1) throw (std::bad_alloc) { return (T )salloc_ (n * sizeof (T), 0); }
180
181	root	1.12	// for symmetry
182	root	1.18	template<typename T>
183	root	1.20	inline void sfree (T *ptr, int n = 1) throw ()
184	root	1.12	{
185	root	1.36	#ifdef PREFER_MALLOC
186			free (ptr);
187			#else
188	root	1.20	g_slice_free1 (n * sizeof (T), (void *)ptr);
189	root	1.36	#endif
190	root	1.12	}
191	root	1.11
192			// a STL-compatible allocator that uses g_slice
193			// boy, this is verbose
194			template<typename Tp>
195			struct slice_allocator
196			{
197			typedef size_t size_type;
198			typedef ptrdiff_t difference_type;
199			typedef Tp *pointer;
200			typedef const Tp *const_pointer;
201			typedef Tp &reference;
202			typedef const Tp &const_reference;
203			typedef Tp value_type;
204
205			template <class U>
206			struct rebind
207			{
208			typedef slice_allocator<U> other;
209			};
210
211			slice_allocator () throw () { }
212			slice_allocator (const slice_allocator &o) throw () { }
213			template<typename Tp2>
214			slice_allocator (const slice_allocator<Tp2> &) throw () { }
215
216			~slice_allocator () { }
217
218			pointer address (reference x) const { return &x; }
219			const_pointer address (const_reference x) const { return &x; }
220
221			pointer allocate (size_type n, const_pointer = 0)
222			{
223	root	1.18	return salloc<Tp> (n);
224	root	1.11	}
225
226			void deallocate (pointer p, size_type n)
227			{
228	root	1.19	sfree<Tp> (p, n);
229	root	1.11	}
230
231			size_type max_size ()const throw ()
232			{
233			return size_t (-1) / sizeof (Tp);
234			}
235
236			void construct (pointer p, const Tp &val)
237			{
238			::new (p) Tp (val);
239			}
240
241			void destroy (pointer p)
242			{
243			p->~Tp ();
244			}
245	root	1.1	};
246
247	root	1.32	// P. L'Ecuyer, “Maximally Equidistributed Combined Tausworthe Generators”, Mathematics of Computation, 65, 213 (1996), 203–213.
248			// http://www.iro.umontreal.ca/~lecuyer/myftp/papers/tausme.ps
249			// http://www.iro.umontreal.ca/~lecuyer/myftp/papers/tausme2.ps
250			struct tausworthe_random_generator
251			{
252	root	1.34	// generator
253	root	1.32	uint32_t state [4];
254
255	root	1.34	void operator =(const tausworthe_random_generator &src)
256			{
257			state [0] = src.state [0];
258			state [1] = src.state [1];
259			state [2] = src.state [2];
260			state [3] = src.state [3];
261			}
262
263			void seed (uint32_t seed);
264	root	1.32	uint32_t next ();
265
266	root	1.34	// uniform distribution
267	root	1.32	uint32_t operator ()(uint32_t r_max)
268			{
269	root	1.34	return is_constant (r_max)
270			? this->next () % r_max
271			: get_range (r_max);
272	root	1.32	}
273
274			// return a number within (min .. max)
275			int operator () (int r_min, int r_max)
276			{
277	root	1.34	return is_constant (r_min) && is_constant (r_max)
278			? r_min + (*this) (max (r_max - r_min + 1, 1))
279			: get_range (r_min, r_max);
280	root	1.32	}
281
282			double operator ()()
283			{
284	root	1.34	return this->next () / (double)0xFFFFFFFFU;
285	root	1.32	}
286	root	1.34
287			protected:
288			uint32_t get_range (uint32_t r_max);
289			int get_range (int r_min, int r_max);
290	root	1.32	};
291
292			typedef tausworthe_random_generator rand_gen;
293
294			extern rand_gen rndm;
295
296	root	1.7	template<class T>
297			struct refptr
298			{
299			T *p;
300
301			refptr () : p(0) { }
302			refptr (const refptr<T> &p) : p(p.p) { if (p) p->refcnt_inc (); }
303			refptr (T *p) : p(p) { if (p) p->refcnt_inc (); }
304			~refptr () { if (p) p->refcnt_dec (); }
305
306			const refptr<T> &operator =(T *o)
307			{
308			if (p) p->refcnt_dec ();
309			p = o;
310			if (p) p->refcnt_inc ();
311
312			return *this;
313			}
314
315			const refptr<T> &operator =(const refptr<T> o)
316			{
317			*this = o.p;
318			return *this;
319			}
320
321			T &operator * () const { return *p; }
322			T *operator ->() const { return p; }
323
324			operator T *() const { return p; }
325			};
326
327	root	1.24	typedef refptr<maptile> maptile_ptr;
328	root	1.22	typedef refptr<object> object_ptr;
329			typedef refptr<archetype> arch_ptr;
330	root	1.24	typedef refptr<client> client_ptr;
331			typedef refptr<player> player_ptr;
332	root	1.22
333	root	1.4	struct str_hash
334			{
335			std::size_t operator ()(const char *s) const
336			{
337			unsigned long hash = 0;
338
339			/* use the one-at-a-time hash function, which supposedly is
340			* better than the djb2-like one used by perl5.005, but
341			* certainly is better then the bug used here before.
342			* see http://burtleburtle.net/bob/hash/doobs.html
343			*/
344			while (*s)
345			{
346			hash += *s++;
347			hash += hash << 10;
348			hash ^= hash >> 6;
349			}
350
351			hash += hash << 3;
352			hash ^= hash >> 11;
353			hash += hash << 15;
354
355			return hash;
356			}
357			};
358
359			struct str_equal
360			{
361			bool operator ()(const char a, const char b) const
362			{
363			return !strcmp (a, b);
364			}
365			};
366
367	root	1.26	template<class T>
368			struct unordered_vector : std::vector<T, slice_allocator<T> >
369	root	1.6	{
370	root	1.11	typedef typename unordered_vector::iterator iterator;
371	root	1.6
372			void erase (unsigned int pos)
373			{
374			if (pos < this->size () - 1)
375			(this)[pos] = (this)[this->size () - 1];
376
377			this->pop_back ();
378			}
379
380			void erase (iterator i)
381			{
382			erase ((unsigned int )(i - this->begin ()));
383			}
384			};
385
386	root	1.26	template<class T, int T::* index>
387			struct object_vector : std::vector<T , slice_allocator<T > >
388			{
389			void insert (T *obj)
390			{
391			assert (!(obj->*index));
392			push_back (obj);
393			obj->*index = this->size ();
394			}
395
396			void insert (T &obj)
397			{
398			insert (&obj);
399			}
400
401			void erase (T *obj)
402			{
403			assert (obj->*index);
404			int pos = obj->*index;
405			obj->*index = 0;
406
407			if (pos < this->size ())
408			{
409			(this)[pos - 1] = (this)[this->size () - 1];
410			(this)[pos - 1]->index = pos;
411			}
412
413			this->pop_back ();
414			}
415
416			void erase (T &obj)
417			{
418			errase (&obj);
419			}
420			};
421
422	root	1.10	// basically does what strncpy should do, but appends "..." to strings exceeding length
423			void assign (char dst, const char src, int maxlen);
424
425			// type-safe version of assign
426	root	1.9	template<int N>
427			inline void assign (char (&dst)[N], const char *src)
428			{
429	root	1.10	assign ((char *)&dst, src, N);
430	root	1.9	}
431
432	root	1.17	typedef double tstamp;
433
434			// return current time as timestampe
435			tstamp now ();
436
437	root	1.25	int similar_direction (int a, int b);
438
439	root	1.1	#endif
440