Provides a type safe mechanism for representing bitwise-or combinations of enum values. More...

Public Typedefs
using	enum_type = E

Public Methods
constexpr	QFlags ()

constexpr	QFlags (const QFlags &other)

constexpr	QFlags (E value)

constexpr	QFlags (EmptyFlag_Type)

constexpr	QFlags (std::initializer_list< E > list)

constexpr	QFlags (std::nullptr_t)

constexpr	operator int_type () const

constexpr bool	operator! () const

constexpr QFlags	operator& (E value) const

constexpr QFlags	operator& (sint_type mask) const

constexpr QFlags	operator& (uint_type mask) const

QFlags &	operator&= (sint_type mask)

QFlags &	operator&= (uint_type mask)

QFlags &	operator= (const QFlags &other)

constexpr QFlags	operator^ (E value) const

constexpr QFlags	operator^ (QFlags other) const

QFlags &	operator^= (E value)

QFlags &	operator^= (QFlags other)

constexpr QFlags	operator\| (E value) const

constexpr QFlags	operator\| (QFlags other) const

QFlags &	operator\|= (E value)

QFlags &	operator\|= (QFlags other)

constexpr QFlags	operator~ () const

bool	testFlag (E value) const

Detailed Description

template<typename E>
class QFlags< E >

The QFlags class provides a type safe mechanism for representing bitwise-or combinations of enum values. The QFlags<E> class is a template class where E is an enum type.

The traditional C++ approach for storing bitwise-or combinations of enum values is to use an int or uint variable. The draw back with this approach is the inability to type check the bitwise-or combination of enum values.

QFlags only allows enum values to be combined with other values from the same enum. For example, QDir::Filters is a typedef for QFlags<QDir::Filter>. This allows code to safely bitwise OR any of the enum values in QDir::Filter.

QDir object;

object->setFilter(QDir::Filters::Files | QDir::Filters::Dirs);

Values from Different Enums

When values do not belong to the same enum a bitwise OR or bitwise AND will result in a compiler warning.

They can be safely combined by using the cs_enum_cast() prior to the bitwise operation. This function will convert an enum value to an quint64 value.

QWidget customFrame;

customFrame.setFrameStyle( cs_enum_cast(QFrame::StyledPanel) | cs_enum_cast(QFrame::Plain) );

Example

To use QFlags with your own enum types add the using as shown below and call the Q_DECLARE_OPERATORS_FOR_FLAGS() macro. This allows using MyClass::Options to store combinations of MyClass::Option values.

class MyClass {
   public:
      enum Option {
         NoOptions    = 0x0,
         ShowTabs     = 0x1,
         ShowAll      = 0x2,
         SqueezeBlank = 0x4
      };
 
      using Options = QFlags<Option>:
};
 
Q_DECLARE_OPERATORS_FOR_FLAGS(MyClass::Options)

Member Typedef Documentation

template<typename E >

QFlags< E >::enum_type

Equivalent to the E template type.

Constructor & Destructor Documentation

template<typename E >

constexpr QFlags< E >::QFlags ( )

inlineconstexpr

Constructs a QFlags object with no flags set.

template<typename E >

constexpr QFlags< E >::QFlags ( EmptyFlag_Type )

inlineconstexpr

Constructs a QFlags object with no flags set.

QFlags<WindowType> type = Qt::EmptyFlag;

template<typename E >

constexpr QFlags< E >::QFlags ( std::nullptr_t )

inlineconstexpr

Constructs a QFlags object with no flags set.

Note: This constructor should not be used and may be deprecated in a future release. Use the QFlags(EmptyFlag_Type) constructor instead.

template<typename E >

constexpr QFlags< E >::QFlags ( std::initializer_list< E > list )

inlineconstexpr

Constructs a QFlags object using the values in list.

template<typename E >

constexpr QFlags< E >::QFlags ( E value )

inlineconstexpr

Constructs a QFlags object storing the given value.

template<typename E >

constexpr QFlags< E >::QFlags ( const QFlags< E > & other )

inlineconstexpr

Copy constructs a new QFlags from other.

Method Documentation

template<typename E >

constexpr QFlags< E >::operator int_type ( ) const

inlineconstexpr

Returns the value stored in the QFlags object as an integer.

template<typename E >

constexpr bool QFlags< E >::operator! ( ) const

inlineconstexpr

Returns true if no flag is set, otherwise returns false.

template<typename E >

constexpr QFlags QFlags< E >::operator& ( E value ) const

inlineconstexpr

Returns a QFlags object containing the result of the bitwise AND operation on this object and value.

template<typename E >

constexpr QFlags QFlags< E >::operator& ( sint_type mask ) const

inlineconstexpr

Returns a QFlags object containing the result of the bitwise AND operation on this object and mask.

See also: operator&=(), operator|(), operator^(), operator~()

template<typename E >

constexpr QFlags QFlags< E >::operator& ( uint_type mask ) const

inlineconstexpr

Returns a QFlags object containing the result of the bitwise AND operation on this object and mask.

template<typename E >

QFlags & QFlags< E >::operator&= ( sint_type mask )

inline

Performs a bitwise AND operation with mask and stores the result in this QFlags object. Returns a reference to this object.

See also: operator&(), operator|=(), operator^=()

template<typename E >

QFlags & QFlags< E >::operator&= ( uint_type mask )

inline

Performs a bitwise AND operation with mask and stores the result in this QFlags object. Returns a reference to this object.

template<typename E >

QFlags & QFlags< E >::operator= ( const QFlags< E > & other )

inline

Copy assigns from other and returns a reference to this object.

template<typename E >

constexpr QFlags QFlags< E >::operator^ ( E value ) const

inlineconstexpr

Returns a QFlags object containing the result of the bitwise XOR operation on this object and value.

template<typename E >

constexpr QFlags QFlags< E >::operator^ ( QFlags< E > other ) const

inlineconstexpr

Returns a QFlags object containing the result of the bitwise XOR operation on this object and other.

See also: operator^=(), operator&(), operator|(), operator~()

template<typename E >

QFlags & QFlags< E >::operator^= ( E value )

inline

Performs a bitwise XOR operation with value and stores the result in this QFlags object. Returns a reference to this object.

template<typename E >

QFlags & QFlags< E >::operator^= ( QFlags< E > other )

inline

Performs a bitwise XOR operation with other and stores the result in this QFlags object. Returns a reference to this object.

See also: operator^(), operator&=(), operator|=()

template<typename E >

constexpr QFlags QFlags< E >::operator| ( E value ) const

inlineconstexpr

Returns a QFlags object containing the result of the bitwise OR operation on this object and value.

template<typename E >

constexpr QFlags QFlags< E >::operator| ( QFlags< E > other ) const

inlineconstexpr

Returns a QFlags object containing the result of the bitwise OR operation on this object and other.

See also: operator|=(), operator^(), operator&(), operator~()

template<typename E >

QFlags & QFlags< E >::operator|= ( E value )

inline

Performs a bitwise OR operation with value and stores the result in this QFlags object. Returns a reference to this object.

template<typename E >

QFlags & QFlags< E >::operator|= ( QFlags< E > other )

inline

Performs a bitwise OR operation with other and stores the result in this QFlags object. Returns a reference to this object.

See also: operator|(), operator&=(), operator^=()

template<typename E >

constexpr QFlags QFlags< E >::operator~ ( ) const

inlineconstexpr

Returns a QFlags object that contains the bitwise negation of this object.

See also: operator&(), operator|(), operator^()

template<typename E >

bool QFlags< E >::testFlag ( E value ) const

inline

Returns true if the value is set, otherwise false.

Public Typedefs

Public Methods

Detailed Description

template<typename E> class QFlags< E >

Values from Different Enums

Example

Member Typedef Documentation

Constructor & Destructor Documentation

Method Documentation

template<typename E>
class QFlags< E >