QFlags Class

label->setAlignment(Qt::AlignLeft | Qt::AlignTop);
label->setAlignment({ });

class MyClass
{
public:
    enum Option {
        NoOptions = 0x0,
        ShowTabs = 0x1,
        ShowAll = 0x2,
        SqueezeBlank = 0x4
    };
    Q_DECLARE_FLAGS(Options, Option)
    ...
};

Q_DECLARE_OPERATORS_FOR_FLAGS(MyClass::Options)

Q_FLAG(Options)

Member Function Documentation

[constexpr noexcept] QFlags::QFlags()

Constructs a QFlags object with no flags set.

[constexpr noexcept] QFlags::QFlags(Enum flags)

Constructs a QFlags object storing the flags.

[constexpr noexcept] QFlags::QFlags(QFlag flag)

Constructs a QFlags object initialized with the integer flag.

The QFlag type is a helper type. By using it here instead of int, we effectively ensure that arbitrary enum values cannot be cast to a QFlags, whereas untyped enum values (i.e., int values) can.

This constructor is only present for 32-bit Enum types. To support all enum sizes, consider the constructor using std::in_place_t.

[constexpr noexcept] QFlags::QFlags(std::initializer_list<Enum> flags)

Constructs a QFlags object initialized with all flags combined using the bitwise OR operator.

See also operator|=() and operator|().

[constexpr noexcept, since 6.9] QFlags::QFlags(std::in_place_t, QFlags<T>::Int flags)

Constructs a QFlags object initialized with the integer flags.

This function was introduced in Qt 6.9.

[default] QFlags::QFlags(const QFlags<T> &other)

Constructs a copy of other.

[static constexpr noexcept, since 6.2] QFlags<T> QFlags::fromInt(QFlags<T>::Int i)

Constructs a QFlags object representing the integer value i.

This function was introduced in Qt 6.2.

[constexpr noexcept] QFlags<T> &QFlags::setFlag(Enum flag, bool on = true)

Sets the flag flag if on is true or unsets it if on is false. Returns a reference to this object.

[constexpr noexcept, since 6.2] bool QFlags::testAnyFlag(Enum flag) const

Returns true if any flag set in flag is also set in this flags object, otherwise false. If flag has no flags set, the return will always be false.

This function was introduced in Qt 6.2.

See also testFlag().

[constexpr noexcept, since 6.2] bool QFlags::testAnyFlags(QFlags<T> flags) const

Returns true if any flag set in flags is also set in this flags object, otherwise false. If flags has no flags set, the return will always be false.

This function was introduced in Qt 6.2.

See also testFlags().

[constexpr noexcept] bool QFlags::testFlag(Enum flag) const

Returns true if the flag flag is set, otherwise false.

See also testAnyFlag().

[constexpr noexcept, since 6.2] bool QFlags::testFlags(QFlags<T> flags) const

Returns true if this flags object matches the given flags.

If flags has any flags set, this flags object matches precisely if all flags set in flags are also set in this flags object. Otherwise, when flags has no flags set, this flags object only matches if it also has no flags set.

This function was introduced in Qt 6.2.

See also testAnyFlags().

[constexpr noexcept, since 6.2] QFlags<T>::Int QFlags::toInt() const

Returns the value stored in the QFlags object as an integer. Note that the returned integer may be signed or unsigned, depending on whether the enum's underlying type is signed or unsigned.

This function was introduced in Qt 6.2.

See also Int.

[constexpr noexcept] QFlags<T>::Int QFlags::operator QFlags<T>::Int() const

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

See also Int.

[constexpr noexcept] bool QFlags::operator!() const

Returns true if no flag is set (i.e., if the value stored by the QFlags object is 0); otherwise returns false.

[constexpr noexcept] QFlags<T> QFlags::operator&(int mask) const

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

This operator is disabled if the QT_TYPESAFE_FLAGS macro is defined. Note that it is not extended to 64-bit for 64-bit QFlags either: for 64-bit support, use the type-safe overload.

See also operator&=(), operator|(), operator^(), and operator~().

[constexpr noexcept] QFlags<T> QFlags::operator&(Enum mask) const

This is an overloaded function.

[constexpr noexcept, since 6.2] QFlags<T> QFlags::operator&(QFlags<T> mask) const

This is an overloaded function.

This function was introduced in Qt 6.2.

[constexpr noexcept] QFlags<T> QFlags::operator&(uint mask) const

This is an overloaded function.

This operator is disabled if the QT_TYPESAFE_FLAGS macro is defined. Note that it is not extended to 64-bit for 64-bit QFlags either: for 64-bit support, use the type-safe overload.

[constexpr noexcept] QFlags<T> &QFlags::operator&=(int mask)

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

This operator is disabled if the QT_TYPESAFE_FLAGS macro is defined. Note that it is not extended to 64-bit for 64-bit QFlags either: for 64-bit support, use the type-safe overload.

See also operator&(), operator|=(), and operator^=().

[constexpr noexcept] QFlags<T> &QFlags::operator&=(Enum mask)

This is an overloaded function.

[constexpr noexcept, since 6.2] QFlags<T> &QFlags::operator&=(QFlags<T> mask)

This is an overloaded function.

This function was introduced in Qt 6.2.

[constexpr noexcept] QFlags<T> &QFlags::operator&=(uint mask)

This is an overloaded function.

This operator is disabled if the QT_TYPESAFE_FLAGS macro is defined. Note that it is not extended to 64-bit for 64-bit QFlags either: for 64-bit support, use the type-safe overload.

[default] int &QFlags::operator=(const QFlags<T> &other)

Assigns other to this object and returns a reference to this object.

[constexpr noexcept] QFlags<T> QFlags::operator^(QFlags<T> other) const

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

See also operator^=(), operator&(), operator|(), and operator~().

[constexpr noexcept] QFlags<T> QFlags::operator^(Enum other) const

This is an overloaded function.

[constexpr noexcept] QFlags<T> &QFlags::operator^=(QFlags<T> other)

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&=(), and operator|=().

[constexpr noexcept] QFlags<T> &QFlags::operator^=(Enum other)

This is an overloaded function.

[constexpr noexcept] QFlags<T> QFlags::operator|(QFlags<T> other) const

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

See also operator|=(), operator^(), operator&(), and operator~().

[constexpr noexcept] QFlags<T> QFlags::operator|(Enum other) const

This is an overloaded function.

[constexpr noexcept] QFlags<T> &QFlags::operator|=(QFlags<T> other)

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&=(), and operator^=().

[constexpr noexcept] QFlags<T> &QFlags::operator|=(Enum other)

This is an overloaded function.

[constexpr noexcept] QFlags<T> QFlags::operator~() const

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

See also operator&(), operator|(), and operator^().

typedef QFlags<Enum> Flags;