[Boost-users] [assign] Default list_of() behavior

Subject: [Boost-users] [assign] Default list_of() behavior
From: Ryan McConnehey (mccorywork_at_[hidden])
Date: 2010-08-05 11:26:02

None of the examples, for list_of, show the use of the default list_of 
constructor.  When I tried to use list_of() for a vector I expected a 
blank vector without any elements.  What I found was a vector that had 
one element of the vector type.  This element had a default value.  Is 
this the correct behavior?

t_ucvector temp( list_of() );  //The temp vector has one element of type 
unsigned char with a default value of zero.

There is a structure with a couple of constant std::vectors that are 
being initializing in the constructor's preamble.  I've included the 
structure with the working version of the code.  I've included the 
desired creation of the std::vector, but because of list_of() is not 
working.

Thank you for your help.

Ryan

struct SplitterFixture
{
public:
  SplitterFixture(void)
  : header(list_of(2)(2))
  , messageA(list_of('a').repeat(2,'a'))
  , input(t_boostVector(new t_ucvector(list_of(2)(2).range(messageA))))

  //Desired implementation.
  //: header(list_of().repeat(2,'2'))
  //, messageA(list_of().repeat(3,'a'))
  //, input(t_boostVector(new 
t_ucvector(list_of().range(header).range(messageA))))
  {}

public:
  typedef std::vector<unsigned char>      t_ucvector;
  typedef boost::shared_ptr<t_ucvector>   t_boostVector;

public:
  t_ucvector      const   header;
  t_ucvector      const   messageA;
  t_boostVector   const   input;
};