--- title: "slint::interpreter::Value Class" --- ```cpp class Value; ``` ```cpp #include ``` This is a dynamically typed value used in the Slint interpreter. It can hold a value of different types, and you should use the different overloaded constructors and the to\_xxx() functions to access the value within. It is also possible to query the type the value holds by calling the [Value::type()](./#type-2) function. Note that models are only represented in one direction: You can create a slint::Model\ in C++, store it in a [std::shared\_ptr](https://en.cppreference.com/w/cpp/memory/shared_ptr) and construct [Value](./) from it. Then you can set it on a property in your .slint code that was declared to be either an array (`property <[sometype]> foo;`) or an object literal (`property <{foo: string, bar: int}> my_prop;`). Such properties are dynamic and accept models implemented in C++. ```cpp Value v(42.0); // Creates a value that holds a double with the value 42. Value some_value = ...; // Check if the value has a string if (std::optional string_value = some_value.to_string()) do_something(*string_value); // Extract the string by de-referencing ``` ## Public Types ### `Type` ```cpp ValueType using slint::interpreter::Value::Type = ValueType ``` A convenience alias for the value type enum. ## Friends ### `operator==` ```cpp bool operator==(const Value &a, const Value &b) ``` Returns true if *a* and *b* hold values of the same type and the underlying vales are equal. ## Public Functions ### `Value` ```cpp slint::interpreter::Value::Value() ``` Constructs a new value of type Value::Type::Void. ### `Value` ```cpp slint::interpreter::Value::Value(const Value &other) ``` Constructs a new value by copying *other*. ### `Value` ```cpp slint::interpreter::Value::Value(Value &&other) ``` Constructs a new value by moving *other* to this. ### `operator=` ```cpp Value & slint::interpreter::Value::operator=(const Value &other) ``` Assigns the value *other* to this. ### `operator=` ```cpp Value & slint::interpreter::Value::operator=(Value &&other) ``` Moves the value *other* to this. ### `~Value` ```cpp slint::interpreter::Value::~Value() ``` Destroys the value. ### `to_number` ```cpp std::optional slint::interpreter::Value::to_number() const ``` Returns a [std::optional](https://en.cppreference.com/w/cpp/utility/optional) that contains a double if the type of this [Value](./) is Type::Double, otherwise an empty optional is returned. ### `to_string` ```cpp std::optional slint::interpreter::Value::to_string() const ``` Returns a [std::optional](https://en.cppreference.com/w/cpp/utility/optional) that contains a string if the type of this [Value](./) is Type::String, otherwise an empty optional is returned. ### `to_bool` ```cpp std::optional slint::interpreter::Value::to_bool() const ``` Returns a [std::optional](https://en.cppreference.com/w/cpp/utility/optional) that contains a bool if the type of this [Value](./) is Type::Bool, otherwise an empty optional is returned. ### `to_array` ```cpp std::optional> slint::interpreter::Value::to_array() const ``` Returns a [std::optional](https://en.cppreference.com/w/cpp/utility/optional) that contains a vector of values if the type of this [Value](./) is Type::Model, otherwise an empty optional is returned. The vector will be constructed by serializing all the elements of the model. ### `to_brush` ```cpp std::optional slint::interpreter::Value::to_brush() const ``` Returns a [std::optional](https://en.cppreference.com/w/cpp/utility/optional) that contains a brush if the type of this [Value](./) is Type::Brush, otherwise an empty optional is returned. ### `to_struct` ```cpp std::optional slint::interpreter::Value::to_struct() const ``` Returns a [std::optional](https://en.cppreference.com/w/cpp/utility/optional) that contains a [Struct](../struct/) if the type of this [Value](./) is Type::Struct, otherwise an empty optional is returned. ### `to_image` ```cpp std::optional slint::interpreter::Value::to_image() const ``` Returns a [std::optional](https://en.cppreference.com/w/cpp/utility/optional) that contains an [Image](../../image/) if the type of this [Value](./) is Type::Image, otherwise an empty optional is returned. ### `Value` ```cpp slint::interpreter::Value::Value(double value) ``` Constructs a new [Value](./) that holds the double *value*. ### `Value` ```cpp slint::interpreter::Value::Value(int value) ``` Constructs a new [Value](./) that holds the int *value*. Internally this is stored as a double and [Value::type()](./#type-2) will return Value::Type::Number. ### `Value` ```cpp slint::interpreter::Value::Value(const SharedString &str) ``` Constructs a new [Value](./) that holds the string *str*. ### `Value` ```cpp slint::interpreter::Value::Value(bool b) ``` Constructs a new [Value](./) that holds the boolean *b*. ### `Value` ```cpp slint::interpreter::Value::Value(const SharedVector &v) ``` Constructs a new [Value](./) that holds the value vector *v* as a model. ### `Value` ```cpp slint::interpreter::Value::Value(const std::shared_ptr> &m) ``` Constructs a new [Value](./) that holds the value model *m*. ### `Value` ```cpp slint::interpreter::Value::Value(const slint::Brush &brush) ``` Constructs a new [Value](./) that holds the brush *b*. ### `Value` ```cpp slint::interpreter::Value::Value(const Struct &struc) ``` Constructs a new [Value](./) that holds the [Struct](../struct/) *struc*. ### `Value` ```cpp slint::interpreter::Value::Value(const Image &img) ``` Constructs a new [Value](./) that holds the [Image](../../image/) *img*. ### `type` ```cpp Type slint::interpreter::Value::type() const ``` Returns the type the variant holds.