Class Value

Defined in File sixtyfps_interpreter.h

Class Documentation

class sixtyfps::interpreter::Value

This is a dynamically typed value used in the SixtyFPS 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() function.

Note that models are only represented in one direction: You can create a sixtyfps::Model<Value> in C++, store it in a std::shared_ptr and construct Value from it. Then you can set it on a property in your .60 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++.

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<sixtyfps::SharedString> string_value = some_value.to_string())
    do_something(*string_value);  // Extract the string by de-referencing

Public Types

using Type = ValueType : A convenience alias for the value type enum.

Public Functions

inline Value(): Constructs a new value of type Value::Type::Void.

inline Value(const Value &other): Constructs a new value by copying other.

inline Value(Value &&other): Constructs a new value by moving other to this.

inline Value &operator=(const Value &other): Assigns the value other to this.

inline Value &operator=(Value &&other): Moves the value other to this.

inline ~Value(): Destroys the value.

inline std::optional<double> to_number() const: Returns a std::optional that contains a double if the type of this Value is Type::Double, otherwise an empty optional is returned.

inline std::optional<sixtyfps::SharedString> to_string() const: Returns a std::optional that contains a string if the type of this Value is Type::String, otherwise an empty optional is returned.

inline std::optional<bool> to_bool() const: Returns a std::optional that contains a bool if the type of this Value is Type::Bool, otherwise an empty optional is returned.

inline std::optional<sixtyfps::SharedVector<Value>> to_array() const: Returns a std::optional that contains a vector of values if the type of this Value is Type::Array, otherwise an empty optional is returned.

inline std::optional<sixtyfps::Brush> to_brush() const: Returns a std::optional that contains a brush if the type of this Value is Type::Brush, otherwise an empty optional is returned.

inline std::optional<Struct> to_struct() const: Returns a std::optional that contains a Struct if the type of this Value is Type::Struct, otherwise an empty optional is returned.

inline std::optional<Image> to_image() const: Returns a std::optional that contains an Image if the type of this Value is Type::Image, otherwise an empty optional is returned.

inline Value(double value): Constructs a new Value that holds the double value.

inline Value(const SharedString &str): Constructs a new Value that holds the string str.

inline Value(bool b): Constructs a new Value that holds the boolean b.

inline Value(const SharedVector<Value> &v): Constructs a new Value that holds the value vector v.

inline Value(const std::shared_ptr<sixtyfps::Model<Value>> &m): Constructs a new Value that holds the value model m.

inline Value(const sixtyfps::Brush &brush): Constructs a new Value that holds the brush b.

inline Value(const Struct &struc): Constructs a new Value that holds the Struct struc.

inline Value(const Image &img): Constructs a new Value that holds the Image img.

inline Type type() const: Returns the type the variant holds.

Friends

inline friend friend bool operator== (const Value &a, const Value &b): Returns true if and hold values of the same type and the underlying vales are equal.

inline friend friend bool operator!= (const Value &a, const Value &b): Returns true if and hold values of the same type and the underlying vales are not equal.