Bool Struct Reference

#include <evo/type.h>

Inheritance diagram for Bool:

Detailed Description

Basic boolean type.

A basic Evo container for boolean values.

• Assigned like a bool:

  Bool val(true);         // Set to true
  val = false;            // Set to false

• Can hold null value:

  Bool val;               // Null by default
  val = false;            // Set to false, no longer null
  val.set();;             // Set to null

• Evaluate as bool to check if non-null and non-false:

  Bool val;               // Null by default
  if (val) {              // false
  }
  if (!val) {             // true
  }
  val = false;
  if (val) {              // false
  }
  val = true;
  if (val) {              // true
  }

• Dereference to get raw value:

  Bool val1;              // Null by default
  if (*val1) {            // Dereference for raw value -- false when null
  }

• Comparison operator overloads:

  Bool val;               // Null by default
  if (*val == false) {    // true: raw value is false
  }
  if (val == false) {     // false: null is not false
  }
  if (val < false) {      // true: null is less than any value
  }
  if (*val < false) {     // false: raw value is false
  }

Public Types
typedef void	EvoNullableType
	Identify as nullable type. More...
typedef bool	Type
	Wrapped type (bool) More...

Public Member Functions
	Bool ()
	Constructor. More...
	Bool (const Bool &val)
	Copy constructor. More...
	Bool (bool val)
	Constructor. More...
int	compare (const Nullable< bool > &val) const
	Comparison. More...
int	compare (bool val) const
	Comparison. More...
bool &	denull ()
	Clears null flag and returns value reference. More...
bool	null () const
	Get whether null. More...
	operator SafeBoolType () const
	Safe (explicit) evaluation as bool type. More...
bool	operator! () const
	Negation operator returns whether null or 0. More...
bool	operator!= (const Nullable< bool > &val) const
	Inequality operator. More...
bool	operator!= (bool val) const
	Inequality operator. More...
const bool &	operator* () const
	Dereference for explicit conversion to underlying type (const). More...
bool &	operator* ()
	Dereference for explicit conversion to underlying type. More...
bool	operator< (const Nullable< bool > &val) const
	Less than operator. More...
bool	operator< (bool val) const
	Less than operator. More...
bool	operator<= (const Nullable< bool > &val) const
	Less than or equal operator. More...
bool	operator<= (bool val) const
	Less than or equal operator. More...
Bool &	operator= (const Bool &val)
	Assignment operator. More...
Bool &	operator= (bool val)
	Assignment operator. More...
Bool &	operator= (ValNull)
	Assignment operator to set as null. More...
bool	operator== (const Nullable< bool > &val) const
	Equality operator. More...
bool	operator== (bool val) const
	Equality operator. More...
bool	operator> (const Nullable< bool > &val) const
	Greater than operator. More...
bool	operator> (bool val) const
	Greater than operator. More...
bool	operator>= (const Nullable< bool > &val) const
	Greater than or equal operator. More...
bool	operator>= (bool val) const
	Greater than or equal operator. More...
Nullable< bool > &	set ()
	Set as null. More...
Nullable< bool > &	set (const Nullable< bool > &src)
	Set as copy of given value. More...
Nullable< bool > &	set (bool src)
	Set as given value. More...
bool	valid () const
	Get whether valid (not null). More...
const bool &	value () const
	Get underlying value (const). More...
bool &	value ()
	Get underlying value. More...

Static Public Attributes
static const int	BITS = 1
	Type size in bits (1) More...
static const int	BYTES = sizeof(bool)
	Type size in bytes, usually 1. More...

Member Typedef Documentation

EvoNullableType

typedef void EvoNullableType

inherited

Identify as nullable type.

Type

typedef bool Type

Wrapped type (bool)

Constructor & Destructor Documentation

Bool() [1/3]

Bool ( )

inline

Constructor.

Bool() [2/3]

Bool ( const Bool &  val )

inline

Copy constructor.

Parameters

val	Value to copy

Bool() [3/3]

Bool ( bool  val )

inline

Constructor.

Parameters

val	Value to set

Member Function Documentation

compare() [1/2]

int compare ( const Nullable< bool > &  val ) const

inlineinherited

Comparison.

Parameters

val	Value to compare to

Returns

Result (<0 if this is less, 0 if equal, >0 if this is greater)

compare() [2/2]

int compare ( bool  val ) const

inlineinherited

Comparison.

• If null, the result is always -1 as null compares as less than any non-null value

Parameters

val	Value to compare to

Returns

Result (<0 if this is less, 0 if equal, >0 if this is greater)

denull()

bool & denull ( )

inlineinherited

Clears null flag and returns value reference.

• Value is unchanged, POD types default to 0 when null
• Useful for updating the underlying value by reference
• Note: Nullable<bool> template specialization returns by value instead of reference

Returns

Whether valid

null()

bool null ( ) const

inlineinherited

Get whether null.

Returns

Whether null

operator SafeBoolType()

operator SafeBoolType ( ) const

inlineinherited

Safe (explicit) evaluation as bool type.

• This is called when object is directly evaluated as a bool, and is equivalent to: !operator!()
• See SafeBool

operator!()

bool operator! ( ) const

inlineinherited

Negation operator returns whether null or 0.

Returns

Whether null or 0

operator!=() [1/2]

bool operator!= ( const Nullable< bool > &  val ) const

inlineinherited

Inequality operator.

Parameters

val	Value to compare to

Returns

Whether inequal

operator!=() [2/2]

bool operator!= ( bool  val ) const

inlineinherited

Inequality operator.

• If null, the result is always true as null is not equal to any non-null value

Parameters

val	Value to compare to

Returns

Whether inequal, true if null

operator*() [1/2]

const bool & operator* ( ) const

inlineinherited

Dereference for explicit conversion to underlying type (const).

Alternative to value().

Returns

Underlying type value

operator*() [2/2]

bool & operator* ( )

inlineinherited

Dereference for explicit conversion to underlying type.

Alternative to value().

Returns

Underlying type value

operator<() [1/2]

bool operator< ( const Nullable< bool > &  val ) const

inlineinherited

Less than operator.

• If null, null is less than any non-null value

Parameters

val	Value to compare to

Returns

Whether less than val

operator<() [2/2]

bool operator< ( bool  val ) const

inlineinherited

Less than operator.

• If null, null is less than any non-null value

Parameters

val	Value to compare to

Returns

Whether less than val

operator<=() [1/2]

bool operator<= ( const Nullable< bool > &  val ) const

inlineinherited

Less than or equal operator.

• If null, null is less than or equal to any value

Parameters

val	Value to compare to

Returns

Whether less than or equal to val, true if null

operator<=() [2/2]

bool operator<= ( bool  val ) const

inlineinherited

Less than or equal operator.

• If null, null is less than or equal to any value

Parameters

val	Value to compare to

Returns

Whether less than or equal to val, true if null

operator=() [1/3]

Bool& operator= ( const Bool &  val )

inline

Assignment operator.

Parameters

val	Value to copy

Returns

This

operator=() [2/3]

Bool& operator= ( bool  val )

inline

Assignment operator.

Parameters

val	Value to set

Returns

This

operator=() [3/3]

Bool& operator= ( ValNull  )

inline

Assignment operator to set as null.

Returns

This

operator==() [1/2]

bool operator== ( const Nullable< bool > &  val ) const

inlineinherited

Equality operator.

Parameters

val	Value to compare to

Returns

Whether equal

operator==() [2/2]

bool operator== ( bool  val ) const

inlineinherited

Equality operator.

• If null, the result is always false as null is not equal to any non-null value

Parameters

val	Value to compare to

Returns

Whether equal, false if null

operator>() [1/2]

bool operator> ( const Nullable< bool > &  val ) const

inlineinherited

Greater than operator.

• If null, null is not greater than any non-null value

Parameters

val	Value to compare to

Returns

Whether greater than val, false if null

operator>() [2/2]

bool operator> ( bool  val ) const

inlineinherited

Greater than operator.

• If null, null is not greater than any non-null value

Parameters

val	Value to compare to

Returns

Whether greater than val, false if null

operator>=() [1/2]

bool operator>= ( const Nullable< bool > &  val ) const

inlineinherited

Greater than or equal operator.

• If null, null is not greater than any non-null value

Parameters

val	Value to compare to

Returns

Whether greater than or equal to val

operator>=() [2/2]

bool operator>= ( bool  val ) const

inlineinherited

Greater than or equal operator.

• If null, null is not greater than any non-null value

Parameters

val	Value to compare to

Returns

Whether greater than or equal to val

set() [1/3]

Nullable<bool >& set ( )

inlineinherited

Set as null.

Returns

This

set() [2/3]

Nullable<bool >& set ( const Nullable< bool > &  src )

inlineinherited

Set as copy of given value.

Parameters

src	Source to copy

Returns

This

set() [3/3]

Nullable<bool >& set ( bool  src )

inlineinherited

Set as given value.

Parameters

src	Source to set

Returns

This

valid()

bool valid ( ) const

inlineinherited

Get whether valid (not null).

Returns

Whether valid

value() [1/2]

const bool & value ( ) const

inlineinherited

Get underlying value (const).

Alternative to operator*().

Returns

Whether valid

value() [2/2]

bool & value ( )

inlineinherited

Get underlying value.

Alternative to operator*().

Returns

Whether valid

Member Data Documentation

BITS

const int BITS = 1

static

Type size in bits (1)

BYTES

const int BYTES = sizeof(bool)

static

Type size in bytes, usually 1.

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

• evo/type.h