libzypp  17.1.1
zypp::Rel Struct Reference

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

◆ 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

◆ Rel() [1/5]

zypp::Rel::Rel ( )
inline

DefaultCtor ANY.

Definition at line 77 of file Rel.h.

◆ Rel() [2/5]

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
PARSEif strval_r is not legal.
Todo:
refine exceptions and check throw.

Definition at line 81 of file Rel.cc.

◆ Rel() [3/5]

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.

◆ Rel() [4/5]

zypp::Rel::Rel ( unsigned  bits_r)
inlineexplicit

Ctor from bits.

Definition at line 106 of file Rel.h.

◆ Rel() [5/5]

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

◆ parseFrom()

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.

◆ isRel()

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.

◆ asString()

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

String representation of relational operator.

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

Definition at line 105 of file Rel.cc.

◆ c_str()

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.

◆ inSwitch()

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.

◆ bits()

unsigned zypp::Rel::bits ( ) const
inline

Enumarator values suitable for libsolv.

Definition at line 145 of file Rel.h.

Friends And Related Function Documentation

◆ operator<<()

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

Stream output.

Definition at line 159 of file Rel.h.

◆ operator==()

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

Definition at line 165 of file Rel.h.

◆ operator!=()

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

Definition at line 169 of file Rel.h.

Member Data Documentation

◆ EQ

const Rel zypp::Rel::EQ
static

Definition at line 50 of file Rel.h.

◆ NE

const Rel zypp::Rel::NE
static

Definition at line 51 of file Rel.h.

◆ LT

const Rel zypp::Rel::LT
static

Definition at line 52 of file Rel.h.

◆ LE

const Rel zypp::Rel::LE
static

Definition at line 53 of file Rel.h.

◆ GT

const Rel zypp::Rel::GT
static

Definition at line 54 of file Rel.h.

◆ GE

const Rel zypp::Rel::GE
static

Definition at line 55 of file Rel.h.

◆ ANY

const Rel zypp::Rel::ANY
static

Definition at line 56 of file Rel.h.

◆ NONE

const Rel zypp::Rel::NONE
static

Definition at line 57 of file Rel.h.

◆ _op

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: