FlatData Samples

A Sample represents an instance of the IDL topic-type and contains the data in serialized format. More...

Classes
class	rti::flat::Sample< OffsetType >
	The generic definition of FlatData topic-types. More...
struct	flat_type_traits< T >
	Given a Sample, an Offset or a Builder, it allows obtaining the other types. More...

Typedefs
typedef rti::flat::Sample < MyFlatFinalOffset >	MyFlatFinal
	Represents an arbitrary user-defined FlatData final IDL struct.
typedef rti::flat::Sample < MyFlatMutableOffset >	MyFlatMutable
	Represents an arbitrary user-defined flat mutable IDL struct.
typedef rti::flat::Sample < MyFlatUnionOffset >	MyFlatUnion
	Represents an arbitrary user-defined flat mutable IDL union.

Detailed Description

A Sample represents an instance of the IDL topic-type and contains the data in serialized format.

All FlatData topic-types are instantiations of rti::flat::Sample. This documentation uses the following three example types to illustrate the different ways FlatData IDL types map to C++:

• MyFlatFinal, the type generated for a final IDL struct
• MyFlatMutable, the type generated for a mutable IDL struct
• MyFlatUnion, the type generated for an IDL union

Typedef Documentation

typedef rti::flat::Sample<MyFlatFinalOffset> MyFlatFinal

Represents an arbitrary user-defined FlatData final IDL struct.

This documentation uses the following example IDL definition of MyFlatFinal:

@language_binding(FLAT_DATA)
@final
struct MyFlatFinal {
    long my_primitive;
    FlatFinalBar my_complex; // Another arbitrary final FlatData type
    long my_primitive_array[10];
    FlatFinalBar my_complex_array[10];
};

For this type, rtiddsgen generates:

• MyFlatFinal (this instantiation of Sample),
• MyFlatFinalOffset.

Note that, as a final FlatData type, MyFlatFinal can only contain fixed-size types, such as primitives, other final FlatData structs, and arrays of fixed-size types.

Samples of MyFlatFinal are created with dds::pub::DataWriter::get_loan. After creating a final Sample, modify its values using the MyFlatFinalOffset returned by root().

typedef rti::flat::Sample<MyFlatMutableOffset> MyFlatMutable

Represents an arbitrary user-defined flat mutable IDL struct.

This documentation uses the following example IDL definition of MyFlatMutable:

@language_binding(FLAT_DATA)
@mutable
struct MyFlatMutable {
    long my_primitive;
    @optional long my_optional_primitive;
    long my_primitive_array[10];
    sequence<long, 10> my_primitive_seq;

    MyFlatFinal my_final;
    MyFlatFinal my_final_array[10];
    sequence<MyFlatFinal, 10> my_final_seq;

    FlatMutableBar my_mutable;
    FlatMutableBar my_mutable_array[10];
    sequence<FlatMutableBar, 10> my_mutable_seq;

    string<255> my_string;
    sequence<string<255>, 10> my_string_seq;
};

For this type, rtiddsgen generates:

• MyFlatMutable (this instantiation of Sample),
• MyFlatMutableOffset,
• MyFlatMutableBuilder.

As a mutable FlatData type, MyFlatMutable is not restricted to fixed-size members. Samples of MyFlatMutable are created with rti::flat::build_data(), which returns a MyFlatMutableBuilder. Once built, a mutable Sample can't change in size, but the value of members that already exist can be changed using the MyFlatMutableOffset returned by root().

typedef rti::flat::Sample<MyFlatUnionOffset> MyFlatUnion

Represents an arbitrary user-defined flat mutable IDL union.

This documentation uses the following example IDL definition of MyFlatUnion:

@language_binding(FLAT_DATA)
@mutable
union MyFlatUnion switch (long) {
    case 0:
        long my_primitive;
    case 1:
    case 2:
        MyFlatMutable my_mutable;
    case 3:
        MyFlatFinal my_final;
};

Note

FlatData unions can only be mutable since unions are, by definition, variable-size types.

For this type, rtiddsgen generates:

• MyFlatUnion (this instantiation of Sample),
• MyFlatUnionOffset,
• MyFlatUnionBuilder.