// util.h - Don Yang (uguu.org)
//
// 05/29/11

#ifndef UTIL_H_
#define UTIL_H_

#include<stdio.h>
#include<stdlib.h>

// Check that a container contains a key
template<typename Container, typename Key>
inline bool ContainsKey(const Container &x, const Key &key)
{
   return x.find(key) != x.end();
}

// Delete all pointer elements in a container
template<typename T>
inline void DeletePtrElements(T *x)
{
   for(typename T::iterator i = x->begin(); i != x->end(); ++i)
      delete *i;
   x->clear();
}

// Clear container by doing a swap with an empty container.  This reduces
// memory footprint a bit more for containers that reserves extra capacity.
template<typename T>
inline void ClearContainer(T *x)
{
   T empty;
   x->swap(empty);
}

// Seek an iterator N positions forward in a container, returns end() if
// the end is reached before then.
template<typename T>
typename T::iterator inline SeekForward(T *x, int steps)
{
   typename T::iterator i = x->begin();
   for(; i != x->end() && steps > 0; steps--)
      ++i;
   return i;
}

template<typename T>
typename T::const_iterator inline SeekForward(const T &x, int steps)
{
   typename T::const_iterator i = x.begin();
   for(; i != x.end() && steps > 0; steps--)
      ++i;
   return i;
}

// Conditionally exit with nonzero status and message
#define CHECK(cond, msg) \
   if( !(cond) )                                        \
   {                                                    \
      printf("%s:%d: %s\n", __FILE__, __LINE__, (msg)); \
      exit(EXIT_FAILURE);                               \
   }

#endif  // UTIL_H_