A dimension of the vector space. More...

#include <ppl.hh>

Classes
struct	Compare
	Binary predicate defining the total ordering on variables. More...

Public Types
typedef void	output_function_type(std::ostream &s, const Variable v)
	Type of output functions.

Public Member Functions
	Variable (dimension_type i)
	Builds the variable corresponding to the Cartesian axis of index `i`. More...

dimension_type	id () const
	Returns the index of the Cartesian axis associated to the variable.

dimension_type	space_dimension () const
	Returns the dimension of the vector space enclosing `*this`. More...

memory_size_type	total_memory_in_bytes () const
	Returns the total size in bytes of the memory occupied by `*this`.

memory_size_type	external_memory_in_bytes () const
	Returns the size in bytes of the memory managed by `*this`.

bool	OK () const
	Checks if all the invariants are satisfied.

void	m_swap (Variable &v)
	Swaps *this and v.

Static Public Member Functions
static dimension_type	max_space_dimension ()
	Returns the maximum space dimension a Variable can handle.

static void	default_output_function (std::ostream &s, const Variable v)
	The default output function.

static void	set_output_function (output_function_type *p)
	Sets the output function to be used for printing Variable objects.

static output_function_type *	get_output_function ()
	Returns the pointer to the current output function.

Related Functions
(Note that these are not member functions.)
std::ostream &	operator<< (std::ostream &s, const Variable v)
	Output operator. More...

bool	less (Variable v, Variable w)
	Defines a total ordering on variables. More...

void	swap (Variable &x, Variable &y)

bool	less (const Variable v, const Variable w)

Detailed Description

A dimension of the vector space.

An object of the class Variable represents a dimension of the space, that is one of the Cartesian axes. Variables are used as basic blocks in order to build more complex linear expressions. Each variable is identified by a non-negative integer, representing the index of the corresponding Cartesian axis (the first axis has index 0). The space dimension of a variable is the dimension of the vector space made by all the Cartesian axes having an index less than or equal to that of the considered variable; thus, if a variable has index $i$ , its space dimension is $i+1$ .

Note that the ``meaning'' of an object of the class Variable is completely specified by the integer index provided to its constructor: be careful not to be mislead by C++ language variable names. For instance, in the following example the linear expressions e1 and e2 are equivalent, since the two variables x and z denote the same Cartesian axis.

Variable x(0);
Variable y(1);
Variable z(0);
Linear_Expression e1 = x + y;
Linear_Expression e2 = y + z;

Constructor & Destructor Documentation

Parma_Polyhedra_Library::Variable::Variable ( dimension_type i )

inlineexplicit

Builds the variable corresponding to the Cartesian axis of index i.

Exceptions

std::length_error Thrown if i+1 exceeds Variable::max_space_dimension().

Member Function Documentation

dimension_type Parma_Polyhedra_Library::Variable::space_dimension ( ) const

inline

Returns the dimension of the vector space enclosing *this.

The returned value is id()+1.

Friends And Related Function Documentation

std::ostream & operator<<	(	std::ostream &	s,
		const Variable	v
	)

bool less	(	Variable	v,
		Variable	w
	)

void swap	(	Variable &	x,
		Variable &	y
	)

bool less	(	const Variable	v,
		const Variable	w
	)

ppl.hh

Classes

Public Types

Public Member Functions

Static Public Member Functions

Related Functions

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation

Friends And Related Function Documentation