## Types

Types — Generic data types

## Synopsis

    typedef             cairo_bool_t;
                        cairo_user_data_key_t;
    void                (*cairo_destroy_func_t)             (void *data);
                        cairo_rectangle_int_t;

## Description

This section lists generic data types used in the cairo API.

## Details

### cairo_bool_t

    typedef int cairo_bool_t;

cairo_bool_t is used for boolean values. Returns of type cairo_bool_t will always be either 0 or 1, but testing against these values explicitly is not encouraged; just use the value as a boolean condition.

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    3

    if (cairo_in_stroke (cr, x, y)) {
        /* do something */
    }

### cairo_user_data_key_t

    typedef struct {
        int unused;
    } cairo_user_data_key_t;

cairo_user_data_key_t is used for attaching user data to cairo data structures. The actual contents of the struct is never used, and there is no need to initialize the object; only the unique address of a cairo_data_key_t object is used. Typically, you would just use the address of a static cairo_data_key_t object.

int `unused`; | not used; ignore.

### cairo_destroy_func_t ()

    void                (*cairo_destroy_func_t)             (void *data);

cairo_destroy_func_t the type of function which is called when a data element is destroyed. It is passed the pointer to the data element and should free any memory and resources allocated for it.

`data` : | The data element being destroyed.

### cairo_rectangle_int_t

    typedef struct {
        int x, y;
        int width, height;
    } cairo_rectangle_int_t;

A data structure for holding a rectangle with integer coordinates.

int `x`; | X coordinate of the left side of the rectangle
int `y`; | Y coordinate of the the top side of the rectangle
int `width`; | width of the rectangle
int `height`; | height of the rectangle

Since 1.10