Represents a length in meters. More...

#include "length.h"

Classes
class	Quantity
	An immutable class which represents a value in a specific length unit. More...

Public Types
enum	Unit : uint16_t { Nanometer = 1 , Micrometer , Millimeter , Centimeter , Meter , Kilometer , NauticalMile , Inch , Foot , Yard , Mile }
	Units of length in various measurement systems that are supported by the Length class. More...

Public Member Functions
	Length ()
	Default Constructor. More...

	Length (const Length &other)=default
	Copy Constructor. More...

	Length (const std::string &text)
	String Constructor. More...

	Length (double value, const std::string &unit)
	Construct a Length object from a value and a unit string. More...

	Length (double value, Length::Unit unit)
	Construct a Length object from a value and a unit. More...

	Length (Length &&other)=default
	Move Constructor. More...

	Length (Quantity quantity)
	Construct a Length object from a Quantity. More...

	~Length ()=default
	Destructor. More...

Quantity	As (Unit unit) const
	Create a Quantity in a specific unit from a Length. More...

double	GetDouble () const
	Current length value. More...

bool	IsEqual (const Length &other, double tolerance=DEFAULT_TOLERANCE) const
	Check if `other` is equal in value to this instance. More...

bool	IsGreater (const Length &other, double tolerance=DEFAULT_TOLERANCE) const
	Check if `other` is less in value than this instance. More...

bool	IsGreaterOrEqual (const Length &other, double tolerance=DEFAULT_TOLERANCE) const
	Check if `other` is equal or less in value than this instance. More...

bool	IsLess (const Length &other, double tolerance=DEFAULT_TOLERANCE) const
	Check if `other` is greater in value than this instance. More...

bool	IsLessOrEqual (const Length &other, double tolerance=DEFAULT_TOLERANCE) const
	Check if `other` is greater or equal in value than this instance. More...

bool	IsNotEqual (const Length &other, double tolerance=DEFAULT_TOLERANCE) const
	Check if `other` is not equal in value to this instance. More...

Length &	operator= (const Length &other)=default
	Copy Assignment operator. More...

Length &	operator= (const Length::Quantity &q)
	Assignment operator. More...

Length &	operator= (Length &&other)=default
	Move Assignment operator. More...

void	swap (Length &other)
	Swap values with another object. More...

Static Public Member Functions
static std::tuple< bool, Length >	TryParse (double value, const std::string &unit)
	Attempt to construct a Length object from a value and a unit string. More...

Static Public Attributes
static constexpr double	DEFAULT_TOLERANCE = std::numeric_limits<double>::epsilon ()
	Default tolerance value used for the member comparison functions (IsEqual, IsLess, etc.) More...

Private Attributes
double	m_value
	Length in meters. More...

Related Functions
(Note that these are not member functions.)
int64_t	Div (const Length &numerator, const Length &denominator, Length *remainder=nullptr)
	Calculate how many times `numerator` can be split into `denominator` sized pieces. More...

std::tuple< bool, Length::Unit >	FromString (std::string unitString)
	Find the equivalent Length::Unit for a unit string. More...

Length	Mod (const Length &numerator, const Length &denominator)
	Calculate the amount remaining after dividing two lengths. More...

bool	operator!= (const Length &l, const Length &r)
	Compare two length objects for inequality. More...

Length	operator* (const Length &left, double scalar)
	Multiply a length value by a scalar. More...

Length	operator* (double scalar, const Length &right)
	Multiply a length value by a scalar. More...

Length	operator+ (const Length &first, const Length &second)
	Add two length values together. More...

Length	operator- (const Length &first, const Length &second)
	Subtract two length values. More...

Length	operator/ (const Length &left, double scalar)
	Divide a length value by a scalar. More...

double	operator/ (const Length &numerator, const Length &denominator)
	Divide a length value by another length value. More...

bool	operator< (const Length &l, const Length &r)
	Check if `l` has a value less than `r`. More...

std::ostream &	operator<< (std::ostream &stream, const Length &l)
	Write a length value to an output stream. More...

std::ostream &	operator<< (std::ostream &stream, const Length::Quantity &q)
	Write a Quantity to an output stream. More...

std::ostream &	operator<< (std::ostream &stream, Length::Unit unit)
	Write a Length::Unit to an output stream. More...

bool	operator<= (const Length &l, const Length &r)
	Check if `l` has a value less than or equal to `r`. More...

bool	operator== (const Length &left, const Length &right)
	Compare two length objects for equality. More...

bool	operator> (const Length &l, const Length &r)
	Check if `l` has a value greater than `r`. More...

bool	operator>= (const Length &l, const Length &r)
	Check if `l` has a value greater than or equal to `r`. More...

std::istream &	operator>> (std::istream &stream, Length &l)
	Read a length value from an input stream. More...

std::string	ToName (Length::Unit unit, bool plural=false)
	Return the name of the supplied unit. More...

std::string	ToSymbol (Length::Unit unit)
	Return the symbol of the supplied unit. More...


Length	NanoMeters (double value)
	Construct a Length from nanometers. More...

Length	MicroMeters (double value)
	Construct a Length from micrometers. More...

Length	MilliMeters (double value)
	Construct a Length from millimeters. More...

Length	CentiMeters (double value)
	Construct a Length from centimeters. More...

Length	Meters (double value)
	Construct a Length from meters. More...

Length	KiloMeters (double value)
	Construct a Length from kilometers. More...

Length	NauticalMiles (double value)
	Construct a Length from nautical miles. More...

Length	Inches (double value)
	Construct a Length from inches. More...

Length	Feet (double value)
	Construct a Length from feet. More...

Length	Yards (double value)
	Construct a Length from yards. More...

Length	Miles (double value)
	Construct a Length from miles. More...

Detailed Description

Represents a length in meters.

The purpose of this class is to replace the use of raw numbers (ints, doubles) that have implicit lengths with a class that represents lengths with an explicit unit. Using raw values with implicit units can lead to bugs when a value is assumed to represent one unit but actually represents another. For example, assuming a value represents a length in meters when it in fact represents a length in kilometers.

The Length class prevents this confusion by storing values internally as doubles representing lengths in Meters and providing conversion functions to convert to/from other length units (kilometers, miles, etc.).

Supported Units

Conversion to and from meters is supported for the following units:

Metric

nanometer
micrometer
millimeter
centimeter
meter
kilometer
nautical mile

US Customary

inch
foot
yard
mile

Construction

Length objects can be constructed in a number of different ways

String Constructor

The string constructor parses strings with the format <number><unit> or <number> <unit> and creates the equivalent Length value in meters. <unit> can be the full name of the unit (nanometer, kilometer, foot, etc.) or the abbreviated name (nm, km, ft, etc.).

//construct lengths from strings
Length foot ("1foot");
Length cm ("1cm");
Length mile ("1 mile");
Length km ("1 km");
 
//nautical mile is special because it is two words
Length nautmile ("1 nautical mile");
Length nmi ("1 nmi");

Quantity Constructor

Quantity is a class that describes a value and a unit type. For example, meter is a unit while 5 meters is a quantity. The Length constructor takes the quantity instance and converts it to the equivalent value in meters.

//construct a Length representing 2 kilometers
Length::Quantity q (2, Length::Unit::Kilometer);
Length km(q);

Value/Unit Constructor

Two constructors are provided which take a value and a unit as separate parameters. The difference between the two constructors is that one takes the unit as a string and the other takes the unit as a Length::Unit value. An assertion is triggered if the string does not map to a valid Length::Unit

//These two contructors are equivalent
Length l1 (1, "cm");
Length l2 (1, Length::Unit::Centimeter);

boost::units

If the boost::units library is discovered during ns-3 configuration an additional constructor is enabled which allows constructing Length objects from boost::unit quantities.

//construct length from a boost::units quantitiy
boost::units::quantity<boost::units::si::length> q = 5 * boost::units::si::meter;
Length meters (q);

Arithmetic Operations

The following arithmetic operations are supported:

Addition

Addition is between two Length instances

std::cout << Length(1, Length::Unit::Meter) + Length (2, Length::Unit::Meter); // output: "3 m"

Subtraction

Subtraction is between two Length instances

std::cout << Length(3, Length::Unit::Meter) - Length (2, Length::Unit::Meter); // output: "1 m"

Multiplication

Multiplication is only supported between a Length and a unitless scalar value

std::cout << Length(1, Length::Unit::Meter) * 5;  // output: "5 m"
 
std::cout << 5 * Length (1, Length::Unit::Meter);  // output: "5 m"

Division

Division can be between a Length and a scalar or two Length objects.

Division between a Length and a scalar returns a new Length.

Division between two Length objects returns a unitless value.

std::cout << Length(5, Length::Unit::Meter) / 5;  // output: "1 m"
 
std::cout << Length (5, Length::Unit::Meter) / Length (5, Length::Unit::Meter);  // output: 1

Comparison Operations

All the usual arithmetic comparison operations (=, !=, <, <=, >, >=) are supported. There are two forms of comparison operators: free function and member function. The free functions define =, !=, <, <=, >, >= and perform exact comparisons of the underlying double values. The Length class provides comparison operator functions (IsEqual, IsLess, IsGreater, etc.) which accept an additional tolerance value to control how much the underlying double values must match when performing the comparison.

//check for exact match
Length l (5, Length::Unit::Meter);
 
bool match = (l == l);  // match is true
 
Length v1 (0.02, Length::Unit::Meter);
Length v2 (0.022, Length::Unit::Meter);
 
match = (v1 == v2);  // match is false
 
double tolerance = 0.01;
bool mostly_match = v1.IsEqual (v2, tolerance);  // mostly_match is true

Serialization

The Length class supports serialization using the << and >> operators. By default the output serialization is in meters. Use Length::As to output the Length value in a different unit.

Length m(5, Length::Unit::Meter);
 
//output: 5 m, 0.005 km, 16.4042 ft
std::cout << m << ", " << m.As(Length::Unit::Kilometer) << ", " << m.As(Length::Unit::Foot);

Definition at line 238 of file length.h.

Member Enumeration Documentation

◆ Unit

enum ns3::Length::Unit : uint16_t

Units of length in various measurement systems that are supported by the Length class.

Enumerator
Nanometer	1e^-9 meters
Micrometer	1e^-6 meters
Millimeter	1e^-3 meters
Centimeter	1e^-2 meters
Meter	Base length unit in metric system.
Kilometer	1e³ meters
NauticalMile	1,852 meters
Inch	1/12 of a foot
Foot	Base length unit in US customary system.
Yard	3 feet
Mile	5,280 feet

Definition at line 245 of file length.h.

Constructor & Destructor Documentation

◆ Length() [1/7]

ns3::Length::Length ( )

Default Constructor.

Initialize with a value of 0 meters.

Definition at line 258 of file length.cc.

References NS_LOG_FUNCTION.

Referenced by TryParse().

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◆ Length() [2/7]

ns3::Length::Length ( const std::string & text )

String Constructor.

Parses text and initializes the value with the parsed result.

The expected format of text is <number> <unit> or <number><unit>

Parameters

text	Serialized length value

Definition at line 264 of file length.cc.

References NS_LOG_FUNCTION.

◆ Length() [3/7]

ns3::Length::Length	(	double	value,
		const std::string &	unit
	)

Construct a Length object from a value and a unit string.

unit can either be the full name of the unit (meter, kilometer, mile, etc.) or the symbol of the unit (m, km, mi, etc.)

Warning: NS_FATAL_ERROR is called if unit is not a valid unit string.; Use Length::TryParse to parse potentially bad values without terminating.

Parameters

value	Numeric value of the new length
unit	Unit that the value represents

Definition at line 274 of file length.cc.

References anonymous_namespace{length.cc}::Convert(), FromString(), m_value, NS_FATAL_ERROR, and NS_LOG_FUNCTION.

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◆ Length() [4/7]

ns3::Length::Length	(	double	value,
		Length::Unit	unit
	)

Construct a Length object from a value and a unit.

Warning: NS_FATAL_ERROR is called if unit is not valid.; Use Length::TryParse to parse potentially bad values without terminating.

Parameters

value	Numeric value of the new length
unit	Length unit of the value

Definition at line 294 of file length.cc.

References anonymous_namespace{length.cc}::Convert(), m_value, and NS_LOG_FUNCTION.

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◆ Length() [5/7]

ns3::Length::Length ( Quantity quantity )

Construct a Length object from a Quantity.

Parameters

quantity Quantity representing a length value and unit

Definition at line 302 of file length.cc.

References NS_LOG_FUNCTION.

◆ Length() [6/7]

ns3::Length::Length ( const Length & other )

default

Copy Constructor.

Initialize an object with the value from other.

Parameters

other Length object to copy

◆ Length() [7/7]

ns3::Length::Length ( Length && other )

default

Move Constructor.

Initialize an object with the value from other.

After the move completes, other is left in an undefined but useable state.

Parameters

other Length object to move

◆ ~Length()

ns3::Length::~Length ( )

default

Destructor.

Member Function Documentation

◆ As()

Length::Quantity ns3::Length::As ( Length::Unit unit ) const

Create a Quantity in a specific unit from a Length.

Converts the current length value to the equivalent value specified by unit and returns a Quantity object with the converted value and unit

Parameters

unit	The desired unit of the returned Quantity

Returns: A quantity representing the length in the requested unit

Definition at line 388 of file length.cc.

References anonymous_namespace{length.cc}::Convert(), m_value, and NS_LOG_FUNCTION.

Referenced by Conversions(), DivAndMod(), operator<<(), LengthTestCase::TestLengthSerialization(), and LengthValueTestCase::TestSetAttributeUsingStringValue().

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◆ GetDouble()

double ns3::Length::GetDouble ( void ) const

Current length value.

Equivalent to:

As (Length::Unit::Meter).Value ()

ns3::Length::Quantity::Value

double Value() const

The value of the quantity.

Definition: length.h:310

ns3::Length::As

Quantity As(Unit unit) const

Create a Quantity in a specific unit from a Length.

Definition: length.cc:388

Returns: The current value, in meters

Definition at line 382 of file length.cc.

References m_value.

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◆ IsEqual()

bool ns3::Length::IsEqual	(	const Length &	other,
		double	tolerance = `DEFAULT_TOLERANCE`
	)		const

Check if other is equal in value to this instance.

Parameters

other	Value to compare against
tolerance	Smallest difference allowed between the two values to still be considered equal

Returns: true if the absolute difference between lengths is less than or equal to tolerance

Definition at line 319 of file length.cc.

References m_value, and NS_LOG_FUNCTION.

Referenced by IsLessOrEqual(), IsNotEqual(), LengthTestCase::TestIsEqualReturnsFalse(), LengthTestCase::TestIsEqualReturnsTrue(), LengthTestCase::TestIsEqualWithToleranceReturnsFalse(), and LengthTestCase::TestIsEqualWithToleranceReturnsTrue().

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◆ IsGreater()

bool ns3::Length::IsGreater	(	const Length &	other,
		double	tolerance = `DEFAULT_TOLERANCE`
	)		const

Check if other is less in value than this instance.

Parameters

other	Value to compare against
tolerance	Smallest difference allowed between the two values to still be considered equal

Equivalent to:

!(IsLessOrEqual(other, tolerance))

ns3::Length::IsLessOrEqual

bool IsLessOrEqual(const Length &other, double tolerance=DEFAULT_TOLERANCE) const

Check if other is greater or equal in value than this instance.

Definition: length.cc:350

Returns: true if the values are not equal and other is less in value

Definition at line 358 of file length.cc.

References IsLessOrEqual(), m_value, and NS_LOG_FUNCTION.

Referenced by LengthTestCase::TestIsGreaterReturnsFalse(), LengthTestCase::TestIsGreaterReturnsTrue(), and LengthTestCase::TestIsGreaterWithToleranceReturnsFalse().

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◆ IsGreaterOrEqual()

bool ns3::Length::IsGreaterOrEqual	(	const Length &	other,
		double	tolerance = `DEFAULT_TOLERANCE`
	)		const

Check if other is equal or less in value than this instance.

Parameters

other	Value to compare against
tolerance	Smallest difference allowed between the two values to still be considered equal

Equivalent to:

!IsLess(other, tolerance)

ns3::Length::IsLess

bool IsLess(const Length &other, double tolerance=DEFAULT_TOLERANCE) const

Check if other is greater in value than this instance.

Definition: length.cc:342

Returns: true if the values are equal or other is less in value

Definition at line 366 of file length.cc.

References IsLess(), m_value, and NS_LOG_FUNCTION.

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◆ IsLess()

bool ns3::Length::IsLess	(	const Length &	other,
		double	tolerance = `DEFAULT_TOLERANCE`
	)		const

Check if other is greater in value than this instance.

Parameters

other	Value to compare against
tolerance	Smallest difference allowed between the two values to still be considered equal

Returns: true if the values are not equal and other is greater in value

Definition at line 342 of file length.cc.

References IsNotEqual(), m_value, and NS_LOG_FUNCTION.

Referenced by IsGreaterOrEqual(), LengthTestCase::TestIsLessReturnsFalse(), LengthTestCase::TestIsLessReturnsTrue(), and LengthTestCase::TestIsLessWithToleranceReturnsFalse().

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◆ IsLessOrEqual()

bool ns3::Length::IsLessOrEqual	(	const Length &	other,
		double	tolerance = `DEFAULT_TOLERANCE`
	)		const

Check if other is greater or equal in value than this instance.

Parameters

other	Value to compare against
tolerance	Smallest difference allowed between the two values to still be considered equal

Equivalent to:

IsEqual(other, tolerance) || IsLess(other, tolerance)

ns3::Length::IsEqual

bool IsEqual(const Length &other, double tolerance=DEFAULT_TOLERANCE) const

Check if other is equal in value to this instance.

Definition: length.cc:319

Returns: true if the values are equal or other is greater in value

Definition at line 350 of file length.cc.

References IsEqual(), m_value, and NS_LOG_FUNCTION.

Referenced by IsGreater().

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◆ IsNotEqual()

bool ns3::Length::IsNotEqual	(	const Length &	other,
		double	tolerance = `DEFAULT_TOLERANCE`
	)		const

Check if other is not equal in value to this instance.

Parameters

other	Value to compare against
tolerance	Smallest difference allowed between the two values to still be considered equal

Returns: true if the absolute difference between lengths is greater than tolerance

Definition at line 334 of file length.cc.

References IsEqual(), m_value, and NS_LOG_FUNCTION.

Referenced by IsLess(), LengthTestCase::TestIsNotEqualReturnsFalse(), LengthTestCase::TestIsNotEqualReturnsTrue(), LengthTestCase::TestIsNotEqualWithToleranceReturnsFalse(), and LengthTestCase::TestIsNotEqualWithToleranceReturnsTrue().

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◆ operator=() [1/3]

Length& ns3::Length::operator= ( const Length & other )

default

Copy Assignment operator.

Replace the current value with the value from other

Parameters

other Length object to copy

Returns: Reference to the updated object

◆ operator=() [2/3]

Length & ns3::Length::operator= ( const Length::Quantity & q )

Assignment operator.

Replace the current value with the value from q

Parameters

q	Quantity holding the value to assign

Returns: Reference to the updated object

Definition at line 309 of file length.cc.

References anonymous_namespace{length.cc}::Convert(), m_value, and NS_LOG_FUNCTION.

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◆ operator=() [3/3]

Length& ns3::Length::operator= ( Length && other )

default

Move Assignment operator.

Replace the current value with the value from other After the move, other is left in an undefined but valid state

Parameters

other Length object to move

Returns: Reference to the updated object

◆ swap()

void ns3::Length::swap ( Length & other )

Swap values with another object.

Swap the current value with the value in other.

Equivalent to:

Length temp(*this);
*this = other;
other = temp;

Parameters

other Length object to swap

Definition at line 374 of file length.cc.

References m_value.

Referenced by operator>>().

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◆ TryParse()

std::tuple< bool, Length > ns3::Length::TryParse	(	double	value,
		const std::string &	unit
	)

static

Attempt to construct a Length object from a value and a unit string.

unit can either be the full name of the unit (meter, kilometer, mile, etc.) or the symbol of the unit (m, km, mi, etc.)

This function will return false if unit does not map to a known type.

Parameters

value	Numeric value of the new length
unit	Unit that the value represents

Returns: A tuple containing the success or failure of the parsing and a Length object. If the boolean element is true, then the Length element contains the parsed result. If the boolean element is false, the value of the Length element is undefined.

Definition at line 239 of file length.cc.

References Length(), FromString(), and NS_LOG_FUNCTION.

Referenced by LengthTestCase::TestTryParseReturnsFalse(), and LengthTestCase::TestTryParseReturnsTrue().

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Friends And Related Function Documentation

◆ Div()

int64_t Div	(	const Length &	numerator,
		const Length &	denominator,
		Length *	remainder = `nullptr`
	)

If the result of numerator / denominator is not a whole number, the result is rounded toward zero to the nearest whole number. The amount remaining after the division can be retrieved by passing a pointer to a Length in remainder. The remainder will be less than denominator and have the same sign as numerator.

NS_FATAL_ERROR is called if denominator is 0.

Parameters

numerator	The value to split
denominator	The length of each split
remainder	Location to store the remainder

Returns: The number of times numerator can be split into denominator sized pieces, rounded down to the nearest whole number

Definition at line 488 of file length.cc.

References GetDouble(), and NS_FATAL_ERROR.

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◆ FromString()

std::tuple< bool, Length::Unit > FromString ( std::string unitString )

The string value can be a symbol or name (plural or singular).

The string comparison ignores case so strings like "NanoMeter", "centiMeter", "METER" will all match the correct unit.

Leading and trailing whitespace are trimmed from the string before searching for a match.

Parameters

unitString String containing the symbol or name of a length unit

Returns: A tuple containing a boolean and a Length::Unit. When the boolean is true, the Length::Unit contains a valid value. When the boolean is false, a match for the string could not be found and the Length::Unit value is undefined

Definition at line 586 of file length.cc.

Referenced by Length(), and TryParse().

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◆ Mod()

Length Mod	(	const Length &	numerator,
		const Length &	denominator
	)

The returned value will be less than denominator and have the same sign as numerator.

NS_FATAL_ERROR is called if denominator is 0.

Parameters

numerator	The value to split
denominator	The length of each split

Returns: The amount remaining after splitting numerator into denominator sized pieces.

Definition at line 507 of file length.cc.

References GetDouble(), and NS_FATAL_ERROR.

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◆ operator!=()

bool operator!=	(	const Length &	l,
		const Length &	r
	)

Equivalent to:

l.IsNotEqual(r, 0);

Parameters

l	Left length object
r	Right length object

Returns: true if l and r do not have the same value

Definition at line 409 of file length.cc.

References GetDouble().

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◆ operator*() [1/2]

Length operator*	(	const Length &	left,
		double	scalar
	)

Multiplies the value left by scalar and returns a new Length object containing the result.

Parameters

left	Length value
scalar	Multiplication factor

Returns: A newly constructed Length object containing the result of left * scalar.

Definition at line 453 of file length.cc.

References GetDouble().

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◆ operator*() [2/2]

Length operator*	(	double	scalar,
		const Length &	right
	)

Multiplies the value right by scalar and returns a new Length object containing the result.

Parameters

scalar	Multiplication factor
right	Length value

Returns: A newly constructed Length object containing the result of right * scalar.

Definition at line 460 of file length.cc.

◆ operator+()

Length operator+	(	const Length &	first,
		const Length &	second
	)

Adds the values of first to second and returns a new Length object containing the result.

Parameters

first	A Length object
second	A Length object

Returns: A newly constructed Length object containing the result of first + second

Definition at line 439 of file length.cc.

References GetDouble().

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◆ operator-()

Length operator-	(	const Length &	first,
		const Length &	second
	)

Subtracts the value of second from first and returns a new Length object containing the result.

Parameters

first	A Length object
second	A Length object

Returns: A newly constructed Length object containing the result of first - second

Definition at line 446 of file length.cc.

References GetDouble().

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◆ operator/() [1/2]

Length operator/	(	const Length &	left,
		double	scalar
	)

Divides the value left by scalar and returns a new Length object containing the result.

scalar must contain a non zero value. NS_FATAL_ERROR is called if scalar is zero

Parameters

left	Length value
scalar	Multiplication factor

Returns: A newly constructed Length object containing the result of left / scalar.

Definition at line 466 of file length.cc.

References NS_FATAL_ERROR.

◆ operator/() [2/2]

double operator/	(	const Length &	numerator,
		const Length &	denominator
	)

Divides the value numerator by the value denominator and returns a scalar value containing the result.

The return value will be NaN if denominator is 0.

Parameters

numerator	The top value of the division
denominator	The bottom value of the division

Returns: A scalar value that is the result of numerator / denominator or NaN if denominator is 0

Definition at line 477 of file length.cc.

References GetDouble().

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◆ operator<()

bool operator<	(	const Length &	l,
		const Length &	r
	)

Equivalent to:

l.IsLess(r, 0);

Parameters

l	Left length object
r	Right length object

Returns: true if l is less than r

Definition at line 414 of file length.cc.

References GetDouble().

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◆ operator<<() [1/3]

std::ostream & operator<<	(	std::ostream &	stream,
		const Length &	l
	)

The output of the length is in meters.

Equivalent to:

stream << l.As (Meter);

ns3::Length::Meter

@ Meter

Base length unit in metric system.

Definition: length.h:252

Parameters

stream	Output stream
l	Length value to write to the stream

Returns: Reference to the output stream

Definition at line 674 of file length.cc.

References As().

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◆ operator<<() [2/3]

std::ostream & operator<<	(	std::ostream &	stream,
		const Length::Quantity &	q
	)

The data written to the output stream will have the format <value> <symbol>

Equivalent to:

stream << q.Value () << ' ' << ToSymbol (q.Unit());

ns3::Length::ToSymbol

std::string ToSymbol(Length::Unit unit)

Return the symbol of the supplied unit.

Definition: length.cc:520

Parameters

stream	Output stream
q	Quantity to write to the output stream

Returns: Reference to the output stream

Definition at line 682 of file length.cc.

References ns3::ToSymbol(), ns3::Length::Quantity::Unit(), and ns3::Length::Quantity::Value().

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◆ operator<<() [3/3]

std::ostream & operator<<	(	std::ostream &	stream,
		Length::Unit	unit
	)

Writes the name of unit to the output stream

Equivalent to:

stream << ToName (unit);

ns3::Length::ToName

std::string ToName(Length::Unit unit, bool plural=false)

Return the name of the supplied unit.

Definition: length.cc:550

Parameters

stream	Output stream
unit	Length unit to output

Returns: Reference to the output stream

Definition at line 690 of file length.cc.

References ns3::ToName().

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◆ operator<=()

bool operator<=	(	const Length &	l,
		const Length &	r
	)

Equivalent to:

l.IsLessOrEqual(r, 0);

Parameters

l	Left length object
r	Right length object

Returns: true if l is less than or equal to r

Definition at line 420 of file length.cc.

References GetDouble().

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◆ operator==()

bool operator==	(	const Length &	left,
		const Length &	right
	)

Equivalent to:

left.IsEqual(right, 0);

Parameters

left	Left length object
right	Right length object

Returns: true if l and r have the same value

Definition at line 403 of file length.cc.

References GetDouble().

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◆ operator>()

bool operator>	(	const Length &	l,
		const Length &	r
	)

Equivalent to:

l.IsGreater(r, 0);

Parameters

l	Left length object
r	Right length object

Returns: true if l is greater than r

Definition at line 427 of file length.cc.

References GetDouble().

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◆ operator>=()

bool operator>=	(	const Length &	l,
		const Length &	r
	)

Equivalent to:

l.IsGreaterOrEqual(r, 0);

Parameters

l	Left length object
r	Right length object

Returns: true if l is greater than or equal to r

Definition at line 433 of file length.cc.

References GetDouble().

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◆ operator>>()

std::istream & operator>>	(	std::istream &	stream,
		Length &	l
	)

The expected format of the input is <number> <unit> or <number><unit> This function calls NS_ABORT if the input stream does not contain a valid length string

Parameters

stream	Input stream
l	Object where the deserialized value will be stored

Returns: Reference to the input stream

Definition at line 750 of file length.cc.

References NS_LOG_LOGIC, ns3::ParseLengthString(), and swap().

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◆ ToName()

std::string ToName	(	Length::Unit	unit,
		bool	plural = `false`
	)

The value returned by this function is the common name of unit. The output is always lowercase.

If plural is true, then the plural form of the common name is returned instead.

Parameters

unit	The unit to name
plural	Boolean indicating if the returned string should contain the plural form of the name

Returns: String containing the full name of unit

Definition at line 550 of file length.cc.

References NS_FATAL_ERROR.

◆ ToSymbol()

std::string ToSymbol ( Length::Unit unit )

The symbol of the unit is the shortened form of the unit name and is usually two or three characters long

Parameters

unit	The unit to symbolize

Returns: String containing the symbol of unit

Definition at line 520 of file length.cc.

References NS_FATAL_ERROR.

Member Data Documentation

◆ DEFAULT_TOLERANCE

constexpr double ns3::Length::DEFAULT_TOLERANCE = std::numeric_limits<double>::epsilon ()

staticconstexpr

Default tolerance value used for the member comparison functions (IsEqual, IsLess, etc.)

The default tolerance is set to epsilon which is defined as the difference between 1.0 and the next value that can be represented by a double.

Definition at line 337 of file length.h.

◆ m_value

double ns3::Length::m_value

private

Length in meters.

Definition at line 611 of file length.h.

Referenced by Length(), As(), GetDouble(), IsEqual(), IsGreater(), IsGreaterOrEqual(), IsLess(), IsLessOrEqual(), IsNotEqual(), operator=(), and swap().

The documentation for this class was generated from the following files:

src/core/model/length.h
src/core/model/length.cc

Classes

Public Types

Public Member Functions

Static Public Member Functions

Static Public Attributes

Private Attributes

Related Functions

Detailed Description

Supported Units

Metric

US Customary

Construction

String Constructor

Quantity Constructor

Value/Unit Constructor

boost::units

Arithmetic Operations

Addition

Subtraction

Multiplication

Division

Comparison Operations

Serialization

Member Enumeration Documentation

◆ Unit

Constructor & Destructor Documentation

◆ Length() [1/7]

◆ Length() [2/7]

◆ Length() [3/7]

◆ Length() [4/7]

◆ Length() [5/7]

◆ Length() [6/7]

◆ Length() [7/7]

◆ ~Length()

Member Function Documentation

◆ As()

◆ GetDouble()

◆ IsEqual()

◆ IsGreater()

◆ IsGreaterOrEqual()

◆ IsLess()

◆ IsLessOrEqual()

◆ IsNotEqual()

◆ operator=() [1/3]

◆ operator=() [2/3]

◆ operator=() [3/3]

◆ swap()

◆ TryParse()

Friends And Related Function Documentation

◆ Div()

◆ FromString()

◆ Mod()

◆ operator!=()

◆ operator*() [1/2]

◆ operator*() [2/2]

◆ operator+()

◆ operator-()

◆ operator/() [1/2]

◆ operator/() [2/2]

◆ operator<()

◆ operator<<() [1/3]

◆ operator<<() [2/3]

◆ operator<<() [3/3]

◆ operator<=()

◆ operator==()

◆ operator>()

◆ operator>=()

◆ operator>>()

◆ ToName()

◆ ToSymbol()

Member Data Documentation

◆ DEFAULT_TOLERANCE

◆ m_value