GIFieldInfo

## GIFieldInfo GIFieldInfo — Struct representing a struct or union field |

## Synopsis

    #define             GI_IS_FIELD_INFO                    (info)
    typedef             GIFieldInfo;
    enum                GIFieldInfoFlags;
    GIFieldInfoFlags    g_field_info_get_flags              (GIFieldInfo *info);
    gint                g_field_info_get_size               (GIFieldInfo *info);
    gint                g_field_info_get_offset             (GIFieldInfo *info);
    GITypeInfo *        g_field_info_get_type               (GIFieldInfo *info);
    gboolean            g_field_info_get_field              (GIFieldInfo *field_info,
                                                             gpointer mem,
                                                             GIArgument *value);
    gboolean            g_field_info_set_field              (GIFieldInfo *field_info,
                                                             gpointer mem,
                                                             const GIArgument *value);

## Description

A GIFieldInfo struct represents a field of a struct (see GIStructInfo), union (see GIUnionInfo) or an object (see GIObjectInfo). The GIFieldInfo is fetched by calling `g_struct_info_get_field()`, `g_union_info_get_field()` or `g_object_info_get_value()`. A field has a size, type and a struct offset asssociated and a set of flags, which is currently GI_FIELD_IS_READABLE or GI_FIELD_IS_WRITABLE.

## Struct hierarchy

      GIBaseInfo
       +----GIFieldInfo

## Details

### GI_IS_FIELD_INFO()

    #define             GI_IS_FIELD_INFO(info)

### GIFieldInfo

    typedef GIBaseInfo GIFieldInfo;

Represents a field of a GIStructInfo or a GIUnionInfo.

### enum GIFieldInfoFlags

    typedef enum {
      GI_FIELD_IS_READABLE = 1 << 0,
      GI_FIELD_IS_WRITABLE = 1 << 1
    } GIFieldInfoFlags;

Flags for a GIFieldInfo.

`GI_FIELD_IS_READABLE` | field is readable.
`GI_FIELD_IS_WRITABLE` | field is writable.

### g_field_info_get_flags ()

    GIFieldInfoFlags    g_field_info_get_flags              (GIFieldInfo *info);

Obtain the flags for this GIFieldInfo. See GIFieldInfoFlags for possible flag values.

`info` : | a GIFieldInfo
Returns : | the flags

### g_field_info_get_size ()

    gint                g_field_info_get_size               (GIFieldInfo *info);

Obtain the size in bits of the field member, this is how much space you need to allocate to store the field.

`info` : | a GIFieldInfo
Returns : | the field size

### g_field_info_get_offset ()

    gint                g_field_info_get_offset             (GIFieldInfo *info);

Obtain the offset in bits of the field member, this is relative to the beginning of the struct or union.

`info` : | a GIFieldInfo
Returns : | the field offset

### g_field_info_get_type ()

    GITypeInfo *        g_field_info_get_type               (GIFieldInfo *info);

Obtain the type of a field as a GITypeInfo.

`info` : | a GIFieldInfo
Returns : | the GITypeInfo. Free the struct by calling `g_base_info_unref()` when done. [transfer full]

### g_field_info_get_field ()

    gboolean            g_field_info_get_field              (GIFieldInfo *field_info,
                                                             gpointer mem,
                                                             GIArgument *value);

Reads a field identified by a GFieldInfo from a C structure or union. This only handles fields of simple C types. It will fail for a field of a composite type like a nested structure or union even if that is actually readable.

`field_info` : | a GIFieldInfo
`mem` : | pointer to a block of memory representing a C structure or union
`value` : | a GIArgument into which to store the value retrieved
Returns : | `TRUE` if reading the field succeeded, otherwise `FALSE`

### g_field_info_set_field ()

    gboolean            g_field_info_set_field              (GIFieldInfo *field_info,
                                                             gpointer mem,
                                                             const GIArgument *value);

Writes a field identified by a GFieldInfo to a C structure or union. This only handles fields of simple C types. It will fail for a field of a composite type like a nested structure or union even if that is actually writable. Note also that that it will refuse to write fields where memory management would by required. A field with a type such as 'char *' must be set with a setter function.

`field_info` : | a GIFieldInfo
`mem` : | pointer to a block of memory representing a C structure or union
`value` : | a GIArgument holding the value to store
Returns : | `TRUE` if writing the field succeeded, otherwise `FALSE`