# Type Mappings The types used for properties in `.slint` design markup each translate to specific types in C++. The follow table summarizes the entire mapping: ```{eval-rst} =========================== =================================== ======================================================================================================================================= :code:`.slint` Type C++ Type Note =========================== =================================== ======================================================================================================================================= :code:`int` :code:`int` :code:`float` :code:`float` :code:`bool` :code:`bool` :code:`string` :cpp:class:`slint::SharedString` A reference-counted string type that uses UTF-8 encoding and can be easily converted to a std::string_view or a :code:`const char *`. :code:`color` :cpp:class:`slint::Color` :code:`brush` :cpp:class:`slint::Brush` :code:`image` :cpp:class:`slint::Image` :code:`physical_length` :code:`float` The unit are physical pixels. :code:`length` :code:`float` At run-time, logical lengths are automatically translated to physical pixels using the device pixel ratio. :code:`duration` :code:`std::int64_t` At run-time, durations are always represented as signed 64-bit integers with millisecond precision. :code:`angle` :code:`float` The angle in degrees. :code:`relative-font-size` :code:`float` Relative font size factor that is multiplied with the :code:`Window.default-font-size` and can be converted to a :code:`length`. structure A :code:`class` of the same name The order of the data member are in the same as in the slint declaration anonymous object A :code:`std::tuple` The fields are in alphabetical order. enum An :code:`enum class` The values are always converted to CamelCase. The order of the values is the same as in the declaration. :code:`Point` :cpp:class:`slint::LogicalPosition` A struct with :code:`x` and :code:`y` fields, representing logical coordinates. =========================== =================================== ======================================================================================================================================= ``` ## Structures The Slint compiler generates a `class` with all data members in the same order for any user-defined, exported `struct` in the `.slint` code. For example, this `struct` in a `.slint` file ```slint,ignore export struct MyStruct { foo: int, bar: string, } ``` will generate the following type in C++: ```cpp class MyStruct { public: int foo; slint::SharedString bar; }; ``` ## Enums The Slint compiler generates an `enum class` with all values in the same order and converted to camel case for any user-defined, exported `enum` in the `.slint` code. For example, this `enum` in a `.slint` file ```slint,ignore export enum MyEnum { alpha, beta-gamma, omicron } ``` will generate the following type in C++: ```cpp enum class MyEnum { Alpha, BetaGamma, Omicron }; ```