rxvt-unicode/src/rxvtutil.h

#ifndef RXVT_UTIL_H
#define RXVT_UTIL_H

#include <cstdlib>
#include <cstring>

#define PP_CONCAT_(a, b) a ## b
#define PP_CONCAT(a, b) PP_CONCAT_(a, b)
#define PP_STRINGIFY_(a) #a
#define PP_STRINGIFY(a) PP_STRINGIFY_(a)

// actually, some gcc-3.x versions work, too
#define HAVE_GCC_BUILTINS (__GNUC__ >= 4)

#ifndef __attribute__
# if __GNUC__
#  if (__GNUC__ == 2 && __GNUC_MINOR__ < 5) || (__GNUC__ < 2)
#   define __attribute__(x)
#  endif
# endif
# define __attribute__(x)
#endif

#define NORETURN __attribute__ ((noreturn))
#define UNUSED   __attribute__ ((unused))
#define CONST    __attribute__ ((const))

// increases code size unless -fno-enforce-eh-specs
#if __GNUC__
# define NOTHROW
# define THROW(x)
#else
# define NOTHROW  throw()
# define THROW(x) throw x
#endif

extern class byteorder {
  static unsigned int e; // at least 32 bits
public:
  byteorder ();

  static bool big_endian    () { return e == 0x11223344; };
  static bool network       () { return e == 0x11223344; };
  static bool little_endian () { return e == 0x44332211; };
  static bool vax           () { return e == 0x44332211; };
} byteorder;

// various utility functions
template<typename T, typename U> static inline T    min    (T  a, U b) { return a < (T)b ? a : (T)b; }
template<typename T, typename U> static inline void min_it (T &a, U b) {    a = a < (T)b ? a : (T)b; }
template<typename T, typename U> static inline T    max    (T  a, U b) { return a > (T)b ? a : (T)b; }
template<typename T, typename U> static inline void max_it (T &a, U b) {    a = a > (T)b ? a : (T)b; }

template<typename T, typename U, typename V> static inline T    clamp    (T  v, U a, V b) { return v < (T)a ? a : v >(T)b ? b : v; }
template<typename T, typename U, typename V> static inline void clamp_it (T &v, U a, V b) {    v = v < (T)a ? a : v >(T)b ? b : v; }

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

// linear interpolation
template<typename T, typename U, typename P>
static inline
T lerp (T a, U b, P p)
{
  return (int(a) * int(p) + int(b) * int(100 - p)) / 100;
}

// some bit functions, xft fuck me plenty
#if HAVE_GCC_BUILTINS
static inline int ctz      (unsigned int x) CONST { return __builtin_ctz      (x); }
static inline int popcount (unsigned int x) CONST { return __builtin_popcount (x); }
#else
// count trailing zero bits and count # of one bits
int ctz      (unsigned int x) CONST;
int popcount (unsigned int x) CONST;
#endif

// 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))

// makes dynamically allocated objects zero-initialised
struct zero_initialized {
  void *operator new (size_t s);
  void operator delete (void *p, size_t s);
};

/* simplevec taken (and heavily modified), from:
 * 
 *  MICO --- a free CORBA implementation
 *  Copyright (C) 1997-98 Kay Roemer & Arno Puder
 */
template<class T>
struct simplevec {
    typedef T* iterator;
    typedef const T* const_iterator;
    typedef unsigned long size_type;

private:
    size_type _last, _size;
    T *_buf;

public:
    const_iterator begin () const
    {
        return &_buf[0];
    }
    iterator begin ()
    {
        return &_buf[0];
    }
    const_iterator end () const
    {
        return &_buf[_last];
    }
    iterator end ()
    {
        return &_buf[_last];
    }
    size_type capacity () const
    {
        return _size;
    }
    size_type size () const
    {
        return _last;
    }

private:
    static T *alloc (size_type n)
    {
        return (T *)::operator new ((size_t) (n * sizeof (T)));
    }
    static void dealloc (T *buf)
    {
        if (buf)
            ::operator delete (buf);
    }

    void reserve (iterator where, size_type n)
    {
        if (_last + n <= _size) {
            memmove (where+n, where, (end ()-where)*sizeof (T));
        } else {
            size_type sz = _last+n;
            sz = (_size == 0) ? max (sz, 5) : max (sz, 2*_size);
            T *nbuf = alloc (sz);
            if (_buf) {
                memcpy (nbuf, begin (), (where-begin ())*sizeof (T));
                memcpy (nbuf + (where-begin ()) + n, where,
                        (end ()-where)*sizeof (T));
                dealloc (_buf);
            }
            _buf = nbuf;
            _size = sz;
        }
    }

public:
    void reserve (size_type sz)
    {
        if (_size < sz) {
            sz = (_size == 0) ? max (sz, 5) : max (sz, 2*_size);
            T *nbuf = alloc (sz);
            if (_buf) {
                memcpy (nbuf, begin (), size ()*sizeof (T));
                dealloc (_buf);
            }
            _buf = nbuf;
            _size = sz;
        }
    }
    simplevec ()
    : _last(0), _size(0), _buf(0)
    {
    }
    simplevec (size_type n, const T& t = T ())
    : _last(0), _size(0), _buf(0)
    {
        insert (begin (), n, t);
    }
    simplevec (const_iterator first, const_iterator last)
    : _last(0), _size(0), _buf(0)
    {
        insert (begin (), first, last);
    }
    simplevec (const simplevec<T> &v)
    : _last(0), _size(0), _buf(0)
    {
        reserve (v._last);
        memcpy (_buf, v.begin (), v.size ()*sizeof (T));
        _last = v._last;
    }
    simplevec<T> &operator= (const simplevec<T> &v)
    {
        if (this != &v) {
            _last = 0;
            reserve (v._last);
            memcpy (_buf, v.begin (), v.size ()*sizeof (T));
            _last = v._last;
        }
        return *this;
    }
    ~simplevec ()
    {
        dealloc (_buf);
    }
    const T &front () const
    {
        //ministl_assert (size () > 0);
        return _buf[0];
    }
    T &front ()
    {
        //ministl_assert (size () > 0);
        return _buf[0];
    }
    const T &back () const
    {
        //ministl_assert (size () > 0);
        return _buf[_last-1];
    }
    T &back ()
    {
        //ministl_assert (size () > 0);
        return _buf[_last-1];
    }
    bool empty () const
    {
        return _last == 0;
    }
    void clear ()
    {
        _last = 0;
    }
    void push_back (const T &t)
    {
        reserve (_last+1);
        *end () = t;
        ++_last;
    }
    void push_back (T &t)
    {
        reserve (_last+1);
        *end () = t;
        ++_last;
    }
    void pop_back ()
    {
        //ministl_assert (size () > 0);
        --_last;
    }
    const T &operator[] (size_type idx) const
    {
        //ministl_assert (idx < size ());
        return _buf[idx];
    }
    T &operator[] (size_type idx)
    {
        //ministl_assert (idx < size ());
        return _buf[idx];
    }
    iterator insert (iterator pos, const T &t)
    {
        //ministl_assert (pos <= end ());
        long at = pos - begin ();
        reserve (pos, 1);
        pos = begin ()+at;
        *pos = t;
        ++_last;
        return pos;
    }
    iterator insert (iterator pos, const_iterator first, const_iterator last)
    {
        //ministl_assert (pos <= end ());
        long n = last - first;
        long at = pos - begin ();
        if (n > 0) {
            reserve (pos, n);
            pos = begin ()+at;
            memcpy (pos, first, (last-first)*sizeof (T));
            _last += n;
        }
        return pos;
    }
    iterator insert (iterator pos, size_type n, const T &t)
    {
        //ministl_assert (pos <= end ());
        long at = pos - begin ();
        if (n > 0) {
            reserve (pos, n);
            pos = begin ()+at;
            for (int i = 0; i < n; ++i)
                pos[i] = t;
            _last += n;
        }
        return pos;
    }
    void erase (iterator first, iterator last)
    {
        if (last != first) {
            memmove (first, last, (end () - last) * sizeof (T));
            _last -= last - first;
        }
    }
    void erase (iterator pos)
    {
        if (pos != end ()) {
            memmove (pos, pos+1, (end () - (pos+1)) * sizeof (T));
            --_last;
        }
    }
    void swap (simplevec<T> &t)
    {
        ::swap(_last, t._last);
        ::swap(_size, t._size);
        ::swap(_buf, t._buf);
    }
};

template<class T>
bool operator== (const simplevec<T> &v1, const simplevec<T> &v2)
{
    if (v1.size () != v2.size ())
        return false;
    return !v1.size () || !memcmp (&v1[0], &v2[0], v1.size ()*sizeof (T));
}

template<class T>
bool operator< (const simplevec<T> &v1, const simplevec<T> &v2)
{
    unsigned long minlast = min (v1.size (), v2.size ());
    for (unsigned long i = 0; i < minlast; ++i) {
        if (v1[i] < v2[i])
            return true;
        if (v2[i] < v1[i])
            return false;
    }
    return v1.size () < v2.size ();
}


template<typename T>
struct vector : simplevec<T>
{ };

#if 0
template<typename T>
struct rxvt_vec : simplevec<void *> {
  typedef T *iterator;

  void push_back (T d) { simplevec<void *>::push_back ((void *)d); }
  T pop_back () { return (T*)simplevec<void *>::pop_back (); }
  void erase (int i) { erase (begin () + i); }
  void erase (iterator i) { simplevec<void *>::erase ((void **)i); }
  iterator begin () const { return (iterator)simplevec<void *>::begin (); }
  iterator end () const { return (iterator)simplevec<void *>::end (); }
  T &operator [] (int i) { return * (T *) (& ((* (simplevec<void *> *)this)[i])); }
  const T &operator [] (int i) const { return * (const T *) (& ((* (const simplevec<void *> *)this)[i])); }
};
#endif

template <typename I, typename T>
I find (I first, I last, const T& value)
{
  while (first != last && *first != value)
    ++first;

  return first;
}

template<typename T>
struct auto_ptr {
  T *p;

  auto_ptr () : p (0) { }
  auto_ptr (T *a) : p (a) { }

  auto_ptr (auto_ptr<T> &a)
  {
    p = a.p;
    a.p = 0;
  }

  template<typename A>
  auto_ptr (auto_ptr<A> &a)
  {
    p = a.p;
    a.p = 0;
  }

  ~auto_ptr ()
  {
    delete p;
  }

  // void because it makes sense in our context
  void operator = (T *a)
  {
    delete p;
    p = a;
  }

  void operator = (auto_ptr &a)
  {
    *this = a.p;
    a.p = 0;
  }

  template<typename A>
  void operator = (auto_ptr<A> &a)
  {
    *this = a.p;
    a.p = 0;
  }

  operator T * () const { return p; }

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

  T *get ()
  {
    T *r = p;
    p = 0;
    return r;
  }
};

typedef auto_ptr<char> auto_str;

struct stringvec : simplevec<char *>
{
  ~stringvec ()
  {
    for (char **c = begin (); c != end (); c++)
      free (*c);
  }
};

// return a very temporary (and never deallocated) buffer. keep small.
void *rxvt_temp_buf (int len);

template<typename T>
static inline T *
rxvt_temp_buf (int len)
{
  return (T *)rxvt_temp_buf (len * sizeof (T));
}

#endif

Revision:	1.24
Committed:	Mon Jan 30 16:12:58 2006 UTC (18 years, 3 months ago) by root
Content type:	text/plain
Branch:	MAIN
Changes since 1.23:	+27 -5 lines
Log Message:	* empty log message *
#	Content
1	#ifndef RXVT_UTIL_H
2	#define RXVT_UTIL_H
3
4	#include <cstdlib>
5	#include <cstring>
6
7	#define PP_CONCAT_(a, b) a ## b
8	#define PP_CONCAT(a, b) PP_CONCAT_(a, b)
9	#define PP_STRINGIFY_(a) #a
10	#define PP_STRINGIFY(a) PP_STRINGIFY_(a)
11
12	// actually, some gcc-3.x versions work, too
13	#define HAVE_GCC_BUILTINS (__GNUC__ >= 4)
14
15	#ifndef __attribute__
16	# if __GNUC__
17	# if (__GNUC__ == 2 && __GNUC_MINOR__ < 5) \|\| (__GNUC__ < 2)
18	# define __attribute__(x)
19	# endif
20	# endif
21	# define __attribute__(x)
22	#endif
23
24	#define NORETURN __attribute__ ((noreturn))
25	#define UNUSED __attribute__ ((unused))
26	#define CONST __attribute__ ((const))
27
28	// increases code size unless -fno-enforce-eh-specs
29	#if __GNUC__
30	# define NOTHROW
31	# define THROW(x)
32	#else
33	# define NOTHROW throw()
34	# define THROW(x) throw x
35	#endif
36
37	extern class byteorder {
38	static unsigned int e; // at least 32 bits
39	public:
40	byteorder ();
41
42	static bool big_endian () { return e == 0x11223344; };
43	static bool network () { return e == 0x11223344; };
44	static bool little_endian () { return e == 0x44332211; };
45	static bool vax () { return e == 0x44332211; };
46	} byteorder;
47
48	// various utility functions
49	template<typename T, typename U> static inline T min (T a, U b) { return a < (T)b ? a : (T)b; }
50	template<typename T, typename U> static inline void min_it (T &a, U b) { a = a < (T)b ? a : (T)b; }
51	template<typename T, typename U> static inline T max (T a, U b) { return a > (T)b ? a : (T)b; }
52	template<typename T, typename U> static inline void max_it (T &a, U b) { a = a > (T)b ? a : (T)b; }
53
54	template<typename T, typename U, typename V> static inline T clamp (T v, U a, V b) { return v < (T)a ? a : v >(T)b ? b : v; }
55	template<typename T, typename U, typename V> static inline void clamp_it (T &v, U a, V b) { v = v < (T)a ? a : v >(T)b ? b : v; }
56
57	template<typename T, typename U> static inline void swap (T& a, U& b) { T t=a; a=(T)b; b=(U)t; }
58
59	// linear interpolation
60	template<typename T, typename U, typename P>
61	static inline
62	T lerp (T a, U b, P p)
63	{
64	return (int(a) * int(p) + int(b) * int(100 - p)) / 100;
65	}
66
67	// some bit functions, xft fuck me plenty
68	#if HAVE_GCC_BUILTINS
69	static inline int ctz (unsigned int x) CONST { return __builtin_ctz (x); }
70	static inline int popcount (unsigned int x) CONST { return __builtin_popcount (x); }
71	#else
72	// count trailing zero bits and count # of one bits
73	int ctz (unsigned int x) CONST;
74	int popcount (unsigned int x) CONST;
75	#endif
76
77	// in range including end
78	#define IN_RANGE_INC(val,beg,end) \
79	((unsigned int)(val) - (unsigned int)(beg) <= (unsigned int)(end) - (unsigned int)(beg))
80
81	// in range excluding end
82	#define IN_RANGE_EXC(val,beg,end) \
83	((unsigned int)(val) - (unsigned int)(beg) < (unsigned int)(end) - (unsigned int)(beg))
84
85	// makes dynamically allocated objects zero-initialised
86	struct zero_initialized {
87	void *operator new (size_t s);
88	void operator delete (void *p, size_t s);
89	};
90
91	/* simplevec taken (and heavily modified), from:
92	*
93	* MICO --- a free CORBA implementation
94	* Copyright (C) 1997-98 Kay Roemer & Arno Puder
95	*/
96	template<class T>
97	struct simplevec {
98	typedef T* iterator;
99	typedef const T* const_iterator;
100	typedef unsigned long size_type;
101
102	private:
103	size_type _last, _size;
104	T *_buf;
105
106	public:
107	const_iterator begin () const
108	{
109	return &_buf[0];
110	}
111	iterator begin ()
112	{
113	return &_buf[0];
114	}
115	const_iterator end () const
116	{
117	return &_buf[_last];
118	}
119	iterator end ()
120	{
121	return &_buf[_last];
122	}
123	size_type capacity () const
124	{
125	return _size;
126	}
127	size_type size () const
128	{
129	return _last;
130	}
131
132	private:
133	static T *alloc (size_type n)
134	{
135	return (T )::operator new ((size_t) (n sizeof (T)));
136	}
137	static void dealloc (T *buf)
138	{
139	if (buf)
140	::operator delete (buf);
141	}
142
143	void reserve (iterator where, size_type n)
144	{
145	if (_last + n <= _size) {
146	memmove (where+n, where, (end ()-where)*sizeof (T));
147	} else {
148	size_type sz = _last+n;
149	sz = (_size == 0) ? max (sz, 5) : max (sz, 2*_size);
150	T *nbuf = alloc (sz);
151	if (_buf) {
152	memcpy (nbuf, begin (), (where-begin ())*sizeof (T));
153	memcpy (nbuf + (where-begin ()) + n, where,
154	(end ()-where)*sizeof (T));
155	dealloc (_buf);
156	}
157	_buf = nbuf;
158	_size = sz;
159	}
160	}
161
162	public:
163	void reserve (size_type sz)
164	{
165	if (_size < sz) {
166	sz = (_size == 0) ? max (sz, 5) : max (sz, 2*_size);
167	T *nbuf = alloc (sz);
168	if (_buf) {
169	memcpy (nbuf, begin (), size ()*sizeof (T));
170	dealloc (_buf);
171	}
172	_buf = nbuf;
173	_size = sz;
174	}
175	}
176	simplevec ()
177	: _last(0), _size(0), _buf(0)
178	{
179	}
180	simplevec (size_type n, const T& t = T ())
181	: _last(0), _size(0), _buf(0)
182	{
183	insert (begin (), n, t);
184	}
185	simplevec (const_iterator first, const_iterator last)
186	: _last(0), _size(0), _buf(0)
187	{
188	insert (begin (), first, last);
189	}
190	simplevec (const simplevec<T> &v)
191	: _last(0), _size(0), _buf(0)
192	{
193	reserve (v._last);
194	memcpy (_buf, v.begin (), v.size ()*sizeof (T));
195	_last = v._last;
196	}
197	simplevec<T> &operator= (const simplevec<T> &v)
198	{
199	if (this != &v) {
200	_last = 0;
201	reserve (v._last);
202	memcpy (_buf, v.begin (), v.size ()*sizeof (T));
203	_last = v._last;
204	}
205	return *this;
206	}
207	~simplevec ()
208	{
209	dealloc (_buf);
210	}
211	const T &front () const
212	{
213	//ministl_assert (size () > 0);
214	return _buf[0];
215	}
216	T &front ()
217	{
218	//ministl_assert (size () > 0);
219	return _buf[0];
220	}
221	const T &back () const
222	{
223	//ministl_assert (size () > 0);
224	return _buf[_last-1];
225	}
226	T &back ()
227	{
228	//ministl_assert (size () > 0);
229	return _buf[_last-1];
230	}
231	bool empty () const
232	{
233	return _last == 0;
234	}
235	void clear ()
236	{
237	_last = 0;
238	}
239	void push_back (const T &t)
240	{
241	reserve (_last+1);
242	*end () = t;
243	++_last;
244	}
245	void push_back (T &t)
246	{
247	reserve (_last+1);
248	*end () = t;
249	++_last;
250	}
251	void pop_back ()
252	{
253	//ministl_assert (size () > 0);
254	--_last;
255	}
256	const T &operator[] (size_type idx) const
257	{
258	//ministl_assert (idx < size ());
259	return _buf[idx];
260	}
261	T &operator[] (size_type idx)
262	{
263	//ministl_assert (idx < size ());
264	return _buf[idx];
265	}
266	iterator insert (iterator pos, const T &t)
267	{
268	//ministl_assert (pos <= end ());
269	long at = pos - begin ();
270	reserve (pos, 1);
271	pos = begin ()+at;
272	*pos = t;
273	++_last;
274	return pos;
275	}
276	iterator insert (iterator pos, const_iterator first, const_iterator last)
277	{
278	//ministl_assert (pos <= end ());
279	long n = last - first;
280	long at = pos - begin ();
281	if (n > 0) {
282	reserve (pos, n);
283	pos = begin ()+at;
284	memcpy (pos, first, (last-first)*sizeof (T));
285	_last += n;
286	}
287	return pos;
288	}
289	iterator insert (iterator pos, size_type n, const T &t)
290	{
291	//ministl_assert (pos <= end ());
292	long at = pos - begin ();
293	if (n > 0) {
294	reserve (pos, n);
295	pos = begin ()+at;
296	for (int i = 0; i < n; ++i)
297	pos[i] = t;
298	_last += n;
299	}
300	return pos;
301	}
302	void erase (iterator first, iterator last)
303	{
304	if (last != first) {
305	memmove (first, last, (end () - last) * sizeof (T));
306	_last -= last - first;
307	}
308	}
309	void erase (iterator pos)
310	{
311	if (pos != end ()) {
312	memmove (pos, pos+1, (end () - (pos+1)) * sizeof (T));
313	--_last;
314	}
315	}
316	void swap (simplevec<T> &t)
317	{
318	::swap(_last, t._last);
319	::swap(_size, t._size);
320	::swap(_buf, t._buf);
321	}
322	};
323
324	template<class T>
325	bool operator== (const simplevec<T> &v1, const simplevec<T> &v2)
326	{
327	if (v1.size () != v2.size ())
328	return false;
329	return !v1.size () \|\| !memcmp (&v1[0], &v2[0], v1.size ()*sizeof (T));
330	}
331
332	template<class T>
333	bool operator< (const simplevec<T> &v1, const simplevec<T> &v2)
334	{
335	unsigned long minlast = min (v1.size (), v2.size ());
336	for (unsigned long i = 0; i < minlast; ++i) {
337	if (v1[i] < v2[i])
338	return true;
339	if (v2[i] < v1[i])
340	return false;
341	}
342	return v1.size () < v2.size ();
343	}
344
345
346	template<typename T>
347	struct vector : simplevec<T>
348	{ };
349
350	#if 0
351	template<typename T>
352	struct rxvt_vec : simplevec<void *> {
353	typedef T *iterator;
354
355	void push_back (T d) { simplevec<void >::push_back ((void )d); }
356	T pop_back () { return (T)simplevec<void >::pop_back (); }
357	void erase (int i) { erase (begin () + i); }
358	void erase (iterator i) { simplevec<void >::erase ((void *)i); }
359	iterator begin () const { return (iterator)simplevec<void *>::begin (); }
360	iterator end () const { return (iterator)simplevec<void *>::end (); }
361	T &operator [] (int i) { return * (T ) (& (( (simplevec<void > )this)[i])); }
362	const T &operator [] (int i) const { return * (const T ) (& (( (const simplevec<void > )this)[i])); }
363	};
364	#endif
365
366	template <typename I, typename T>
367	I find (I first, I last, const T& value)
368	{
369	while (first != last && *first != value)
370	++first;
371
372	return first;
373	}
374
375	template<typename T>
376	struct auto_ptr {
377	T *p;
378
379	auto_ptr () : p (0) { }
380	auto_ptr (T *a) : p (a) { }
381
382	auto_ptr (auto_ptr<T> &a)
383	{
384	p = a.p;
385	a.p = 0;
386	}
387
388	template<typename A>
389	auto_ptr (auto_ptr<A> &a)
390	{
391	p = a.p;
392	a.p = 0;
393	}
394
395	~auto_ptr ()
396	{
397	delete p;
398	}
399
400	// void because it makes sense in our context
401	void operator = (T *a)
402	{
403	delete p;
404	p = a;
405	}
406
407	void operator = (auto_ptr &a)
408	{
409	*this = a.p;
410	a.p = 0;
411	}
412
413	template<typename A>
414	void operator = (auto_ptr<A> &a)
415	{
416	*this = a.p;
417	a.p = 0;
418	}
419
420	operator T * () const { return p; }
421
422	T *operator -> () const { return p; }
423	T &operator * () const { return *p; }
424
425	T *get ()
426	{
427	T *r = p;
428	p = 0;
429	return r;
430	}
431	};
432
433	typedef auto_ptr<char> auto_str;
434
435	struct stringvec : simplevec<char *>
436	{
437	~stringvec ()
438	{
439	for (char **c = begin (); c != end (); c++)
440	free (*c);
441	}
442	};
443
444	// return a very temporary (and never deallocated) buffer. keep small.
445	void *rxvt_temp_buf (int len);
446
447	template<typename T>
448	static inline T *
449	rxvt_temp_buf (int len)
450	{
451	return (T )rxvt_temp_buf (len sizeof (T));
452	}
453
454	#endif
455