QMetaEnum Class

The QMetaEnum class provides meta-data about an enumerator. More…

List of all members, including inherited members

Public Functions

Static Public Members

Detailed Description

Use it to convert between the values of an enumeration declared with Q_ENUM() or Q_FLAG() and their names:

QMetaEnum e = QMetaEnum::fromType<Shape::Kind>();
e.valueToKey(Shape::Circle);   // "Circle"
e.keyToValue("Square");        // Shape::Square

See also QMetaObject::enumerator() and QMetaProperty::enumerator().

Differences from Qt

Member Function Documentation

QMetaEnum::QMetaEnum()

Constructs an invalid enumerator.

See also isValid().

const QMetaObject * QMetaEnum::enclosingMetaObject() const

Returns the meta-object of the class or namespace that declares the enumeration.

const char * QMetaEnum::enumName() const

Returns the name of the enumeration, without its scope. For a flags type this is the name of the flags type.

See also name().

template <typename T>[static] QMetaEnum QMetaEnum::fromType()

Returns the meta-data of the enumeration T, which must be declared with Q_ENUM() or Q_FLAG() (or the _NS forms). Returns an invalid object otherwise.

bool QMetaEnum::is64Bit() const

Returns false: the enumerations that ntmoc records have int values.

This function was introduced in 6.9.

See also value64().

bool QMetaEnum::isFlag() const

Returns true if the enumeration is a set of flags declared with Q_FLAG().

See also keysToValue().

bool QMetaEnum::isScoped() const

Returns true if the enumeration is an enum class.

bool QMetaEnum::isValid() const

Returns true if this object describes an enumerator; otherwise returns false.

const char * QMetaEnum::key(int i) const

Returns the key at i, or nullptr if i is out of range.

See also value() and keyCount().

int QMetaEnum::keyCount() const

Returns the number of keys.

See also key() and value().

int QMetaEnum::keysToValue(const char *keys, bool *ok = nullptr) const

Returns the combined value of the keys in keys, which are separated by |, such as "Read|Write". Returns -1 and sets ok to false if a key is unknown; otherwise sets ok to true if it is not nullptr.

See also valueToKeys() and keyToValue().

int QMetaEnum::keyToValue(const char *key, bool *ok = nullptr) const

Returns the value of the key key, which may be qualified with the scope, such as "Mode::Up" or "Counter::Up". Returns -1 if there is no such key and sets ok to false; otherwise sets ok to true if it is not nullptr.

See also valueToKey() and keysToValue().

std::optional<quint64> QMetaEnum::keyToValue64(const char *key) const

Returns the value of key as a 64-bit number, or std::nullopt if the enumeration has no such key.

This function was introduced in 6.9.

See also keyToValue().

const char * QMetaEnum::name() const

Returns the name of the enumerator, without its scope.

See also enumName() and scope().

const char * QMetaEnum::scope() const

Returns the name of the class or namespace that declares the enumeration.

See also name().

int QMetaEnum::value(int i) const

Returns the value of the key at i, or -1 if i is out of range.

See also key().

std::optional<quint64> QMetaEnum::value64(int i) const

Returns the value of the key at i as a 64-bit number, sign-extended, or std::nullopt if i is out of range.

This function was introduced in 6.9.

See also value() and keyCount().

const char * QMetaEnum::valueToKey(int value) const

Returns the key of the first enumerator with the value value, or nullptr if there is none.

See also keyToValue() and valueToKeys().

QByteArray QMetaEnum::valueToKeys(int value) const

Returns the keys whose values are set in value, separated by |. A value of 0 gives the key whose value is 0, if there is one. Bits that no key accounts for are ignored.

See also keysToValue() and valueToKey().