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#ifndef UTIL_H__ |
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#define UTIL_H__ |
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|
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#if __GNUC__ >= 3 |
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# define is_constant(c) __builtin_constant_p (c) |
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#else |
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# define is_constant(c) 0 |
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#endif |
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|
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// makes dynamically allocated objects zero-initialised |
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struct zero_initialised |
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{ |
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void *operator new (size_t s, void *); |
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void *operator new (size_t s); |
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void *operator new [] (size_t s); |
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void operator delete (void *p, size_t s); |
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void operator delete [] (void *p, size_t s); |
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}; |
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|
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struct refcounted |
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{ |
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mutable int refcnt; |
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refcounted () : refcnt (0) { } |
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void refcnt_inc () { ++refcnt; } |
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void refcnt_dec () { --refcnt; |
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if (refcnt < 0)abort();}//D |
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}; |
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|
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template<class T> |
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struct refptr |
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{ |
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T *p; |
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|
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refptr () : p(0) { } |
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refptr (const refptr<T> &p) : p(p.p) { if (p) p->refcnt_inc (); } |
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refptr (T *p) : p(p) { if (p) p->refcnt_inc (); } |
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~refptr () { if (p) p->refcnt_dec (); } |
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|
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const refptr<T> &operator =(T *o) |
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{ |
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if (p) p->refcnt_dec (); |
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p = o; |
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if (p) p->refcnt_inc (); |
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|
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return *this; |
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} |
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|
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const refptr<T> &operator =(const refptr<T> o) |
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{ |
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*this = o.p; |
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return *this; |
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} |
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|
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T &operator * () const { return *p; } |
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T *operator ->() const { return p; } |
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|
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operator T *() const { return p; } |
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}; |
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|
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struct str_hash |
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{ |
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std::size_t operator ()(const char *s) const |
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{ |
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unsigned long hash = 0; |
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|
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/* use the one-at-a-time hash function, which supposedly is |
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* better than the djb2-like one used by perl5.005, but |
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* certainly is better then the bug used here before. |
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* see http://burtleburtle.net/bob/hash/doobs.html |
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*/ |
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while (*s) |
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{ |
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hash += *s++; |
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hash += hash << 10; |
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hash ^= hash >> 6; |
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} |
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|
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hash += hash << 3; |
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hash ^= hash >> 11; |
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hash += hash << 15; |
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|
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return hash; |
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} |
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}; |
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|
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struct str_equal |
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{ |
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bool operator ()(const char *a, const char *b) const |
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{ |
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return !strcmp (a, b); |
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} |
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}; |
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|
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#include <vector> |
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|
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template<class obj> |
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struct unordered_vector : std::vector<obj> |
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{ |
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typedef typename std::vector<obj>::iterator iterator; |
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|
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void erase (unsigned int pos) |
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{ |
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if (pos < this->size () - 1) |
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(*this)[pos] = (*this)[this->size () - 1]; |
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|
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this->pop_back (); |
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} |
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|
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void erase (iterator i) |
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{ |
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erase ((unsigned int )(i - this->begin ())); |
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} |
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}; |
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|
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template<typename T, typename U> static inline T min (T a, U b) { return a < (T)b ? a : (T)b; } |
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template<typename T, typename U> static inline T max (T a, U b) { return a > (T)b ? a : (T)b; } |
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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; } |
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template<typename T, typename U> static inline void swap (T& a, U& b) { T t=a; a=(T)b; b=(U)t; } |
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|
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// basically does what strncpy should do |
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template<int N> |
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inline void assign (char (&dst)[N], const char *src) |
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{ |
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// should be optimised at some point, maybe should also add "..." |
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// when buffer is too small. |
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snprintf (dst, N, "%s", src); |
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} |
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#endif |
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