bgeot_comma_init.h

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/* -*- c++ -*- (enables emacs c++ mode) */
/*===========================================================================
 
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/**@file bgeot_comma_init.h
   @author  Julien Pommier <[email protected]>
   @date March 27, 2003.
   @brief convenient initialization of vectors via overload of "operator,".
   @code
   std::vector<double> foo; bgeot::sc(foo) += 1,3,4;
   @endcode
 
   highly inspired by the boost init.hpp (C) Thorsten Ottosen
   (http://www.cs.auc.dk/~nesotto/init/)    
*/
#ifndef COMMA_INIT
#define COMMA_INIT
 
namespace bgeot {
 
  /**
   *  Template class which forwards insertions to the
   *  container class.
   */ 
  template<typename Container> class Comma_initializer {
    typedef typename Container::value_type       value_type;
    Container& c_;
  public: 
    explicit Comma_initializer( Container& c ) : c_( c ) {}
    
    Comma_initializer& operator,(const value_type& v) {
      c_.push_back(v);
      return *this;
    }
    
    /**
     *  Should only be used with first value. The operator
     *  gives a nice syntax for initializing the container.
     */
    Comma_initializer& operator=(const value_type v) {
      c_.clear();
      c_.push_back(v);
      return *this;
    }
    /**
     *  Should only be used with first value. The operator
     *  gives a nice syntax for appending to the container.
     */
    Comma_initializer& operator+=(value_type v) {
      c_.push_back(v);
      return *this;
    }
  };
 
  template<typename T> Comma_initializer<T> sc( T& c )
    { return Comma_initializer<T>(c); }
 
}
 
#endif