Relational operators. More...

#include <Rel.h>

Public Types
enum	for_use_in_switch { NONE_e = 0U, GT_e = 1U, EQ_e = 2U, LT_e = 4U, GE_e = GT_e\|EQ_e, LE_e = LT_e\|EQ_e, NE_e = GT_e\|LT_e, ANY_e = GT_e\|EQ_e\|LT_e }
	Enumarators provided only for use inSwitch statement. More...

Public Member Functions
	Rel ()
	DefaultCtor ANY. More...

	Rel (const std::string &strval_r)
	Ctor from string. More...

	Rel (const std::string &strval_r, const Rel &default_r)
	Ctor from string (non-throwing). More...

bool	parseFrom (const std::string &strval_r)
	Assign from string IFF it contains a legal value. More...

	Rel (unsigned bits_r)
	Ctor from bits. More...

const std::string &	asString () const
	String representation of relational operator. More...

const char *	c_str () const

for_use_in_switch	inSwitch () const
	Enumarator provided for use in `switch` statement. More...

unsigned	bits () const
	Enumarator values suitable for libsolv. More...

Static Public Member Functions
static bool	isRel (unsigned bits_r)
	Test whether bits_r is a valid Rel (no extra bits set). More...

Static Public Attributes
Relational operators
These are the real relational operator contants to use. Don't mind that it's not an enum. See also: zypp::Rel::inSwitch
static const Rel	EQ

static const Rel	NE

static const Rel	LT

static const Rel	LE

static const Rel	GT

static const Rel	GE

static const Rel	ANY

static const Rel	NONE

Private Member Functions
	Rel (for_use_in_switch op_r)
	Ctor to initialize the relational operator contants. More...

Private Attributes
for_use_in_switch	_op
	The operator. More...

Related Functions
(Note that these are not member functions.)
std::ostream &	operator<< (std::ostream &str, const Rel &obj)

bool	operator== (const Rel &lhs, const Rel &rhs)

bool	operator!= (const Rel &lhs, const Rel &rhs)

Detailed Description

Relational operators.

Yes, it could as well be simply an enum.
Yes, you can use the relational operators as if it was an enum.
Except for use in a switch statement; see inSwitch for this.

But we want to construct them from a string representation, as well as providing one. And this way they are wrapped into a namespace, which is a good idea anyway.

ANY and NONE are somewhat special. ANY is the operator created by the default ctor, and it should always resolve to true. This may be handy in queries when you're looking for a Resolvable in ANY Edition if no operator was specified. While NONE should always resolve to false.

Definition at line 43 of file Rel.h.

Member Enumeration Documentation

enum zypp::Rel::for_use_in_switch

Enumarators provided only for use inSwitch statement.

See Also: inSwitch

Note: Enumarator values also correspond to the values libsolv uses to encode these relations.

Enumerator
NONE_e
GT_e
EQ_e
LT_e
GE_e
LE_e
NE_e
ANY_e

Definition at line 65 of file Rel.h.

Constructor & Destructor Documentation

zypp::Rel::Rel ( )

inline

DefaultCtor ANY.

Definition at line 77 of file Rel.h.

zypp::Rel::Rel ( const std::string & strval_r )

explicit

Ctor from string.

Legal values for strval_r are: "==", "!=", "<", "<=", ">", ">=",
as well as "EQ", "NE", "LT", "LE", "GT", "GE", "ANY", "NONE"
and "" (empty string resolves to ANY).

Lower case names are accepted as well.

Exceptions

PARSE if strval_r is not legal.

Todo:: refine exceptions and check throw.

Definition at line 81 of file Rel.cc.

zypp::Rel::Rel	(	const std::string &	strval_r,
		const Rel &	default_r
	)

Ctor from string (non-throwing).

Illegal string values resolve to default_r

Definition at line 85 of file Rel.cc.

zypp::Rel::Rel ( unsigned bits_r )

inlineexplicit

Ctor from bits.

Definition at line 106 of file Rel.h.

zypp::Rel::Rel ( for_use_in_switch op_r )

inlineprivate

Ctor to initialize the relational operator contants.

Definition at line 150 of file Rel.h.

Member Function Documentation

bool zypp::Rel::parseFrom ( const std::string & strval_r )

Assign from string IFF it contains a legal value.

Returns: Whether strval_r contained a legal value.

Definition at line 89 of file Rel.cc.

static bool zypp::Rel::isRel ( unsigned bits_r )

inlinestatic

Test whether bits_r is a valid Rel (no extra bits set).

Definition at line 111 of file Rel.h.

const std::string & zypp::Rel::asString ( ) const

String representation of relational operator.

Returns: "==", "!=", "<", "<=", ">", ">=", "ANY" or "NONE"

Definition at line 105 of file Rel.cc.

const char* zypp::Rel::c_str ( ) const

inline

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Definition at line 119 of file Rel.h.

for_use_in_switch zypp::Rel::inSwitch ( ) const

inline

Enumarator provided for use in switch statement.

The sole reason for providing enum for_use_in_switch is, that we may want to use the relational operators in a switch statement. Tht's the only case where you should have to use the enumarator.

Rel op;
switch ( op.inSwitch() )
  {
  case Rel::EQ_e:
    ...
    break;
  case Rel::NE_e:
    ...
  // No default! Let compiler warn if case is missing
  }

Definition at line 141 of file Rel.h.

unsigned zypp::Rel::bits ( ) const

inline

Enumarator values suitable for libsolv.

Definition at line 145 of file Rel.h.

Friends And Related Function Documentation

std::ostream & operator<<	(	std::ostream &	str,
		const Rel &	obj
	)

Definition at line 159 of file Rel.h.

bool operator==	(	const Rel &	lhs,
		const Rel &	rhs
	)

bool operator!=	(	const Rel &	lhs,
		const Rel &	rhs
	)

Member Data Documentation

const Rel zypp::Rel::EQ

static

Definition at line 50 of file Rel.h.

const Rel zypp::Rel::NE

static

Definition at line 51 of file Rel.h.

const Rel zypp::Rel::LT

static

Definition at line 52 of file Rel.h.

const Rel zypp::Rel::LE

static

Definition at line 53 of file Rel.h.

const Rel zypp::Rel::GT

static

Definition at line 54 of file Rel.h.

const Rel zypp::Rel::GE

static

Definition at line 55 of file Rel.h.

const Rel zypp::Rel::ANY

static

Definition at line 56 of file Rel.h.

const Rel zypp::Rel::NONE

static

Definition at line 57 of file Rel.h.

for_use_in_switch zypp::Rel::_op

private

The operator.

Definition at line 154 of file Rel.h.

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

zypp/Rel.h
zypp/Rel.cc

Public Types

Public Member Functions

Static Public Member Functions

Static Public Attributes

Private Member Functions

Private Attributes

Related Functions

Detailed Description

Member Enumeration Documentation

Constructor & Destructor Documentation

Member Function Documentation

Friends And Related Function Documentation

Member Data Documentation