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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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#include <cstddef> |
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|
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#include <glib.h> |
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|
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// use a gcc extension for auto declarations until ISO C++ sanctifies them |
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#define AUTODECL(var,expr) typeof(expr) var = (expr) |
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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 *p) |
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{ |
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memset (p, 0, s); |
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return p; |
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} |
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|
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void *operator new (size_t s) |
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{ |
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return g_slice_alloc0 (s); |
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} |
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|
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void *operator new[] (size_t s) |
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{ |
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return g_slice_alloc0 (s); |
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} |
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|
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void operator delete (void *p, size_t s) |
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{ |
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g_slice_free1 (s, p); |
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} |
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|
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void operator delete[] (void *p, size_t s) |
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{ |
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g_slice_free1 (s, p); |
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} |
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}; |
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|
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// strictly the same as g_slice_alloc, but never returns 0 |
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void *alloc (int s) throw (std::bad_alloc); |
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// for symmetry |
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inline void dealloc (void *p, int s) throw () |
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{ |
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g_slice_free1 (s, p); |
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} |
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|
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// a STL-compatible allocator that uses g_slice |
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// boy, this is verbose |
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template<typename Tp> |
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struct slice_allocator |
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{ |
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typedef size_t size_type; |
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typedef ptrdiff_t difference_type; |
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typedef Tp *pointer; |
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typedef const Tp *const_pointer; |
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typedef Tp &reference; |
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typedef const Tp &const_reference; |
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typedef Tp value_type; |
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|
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template <class U> |
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struct rebind |
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{ |
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typedef slice_allocator<U> other; |
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}; |
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|
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slice_allocator () throw () { } |
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slice_allocator (const slice_allocator &o) throw () { } |
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template<typename Tp2> |
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slice_allocator (const slice_allocator<Tp2> &) throw () { } |
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|
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~slice_allocator () { } |
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|
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pointer address (reference x) const { return &x; } |
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const_pointer address (const_reference x) const { return &x; } |
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|
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pointer allocate (size_type n, const_pointer = 0) |
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{ |
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return static_cast<pointer>(alloc (n * sizeof (Tp))); |
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} |
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|
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void deallocate (pointer p, size_type n) |
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{ |
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dealloc (static_cast<void *>(p), n * sizeof (Tp)); |
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} |
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|
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size_type max_size ()const throw () |
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{ |
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return size_t (-1) / sizeof (Tp); |
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} |
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|
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void construct (pointer p, const Tp &val) |
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{ |
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::new (p) Tp (val); |
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} |
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|
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void destroy (pointer p) |
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{ |
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p->~Tp (); |
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} |
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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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}; |
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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, slice_allocator<obj> > |
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{ |
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typedef typename unordered_vector::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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|
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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, but appends "..." to strings exceeding length |
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void assign (char *dst, const char *src, int maxlen); |
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|
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// type-safe version of assign |
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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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assign ((char *)&dst, src, N); |
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} |
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|
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#endif |
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