# dmd.dstruct

Struct and union declarations.

Specification: Structs, Unions

#### Authors

Walter Bright

#### License

Boost License 1.0

Source: dstruct.d

Documentation: https://dlang.org/phobos/dmd_dstruct.html

Coverage: https://codecov.io/gh/dlang/dmd/src/master/src/dmd/dstruct.d

- `search_toString`

  #### Declaration

  `FuncDeclaration `search_toString`(StructDeclaration `sd`);`

  Search `sd` for a member function of the form: `extern (D) string toString();`

  #### Parameters

  `StructDeclaration `sd`` | struct declaration to search

  #### Return Value

  FuncDeclaration of `toString()` if found, `null` if not

- `semanticTypeInfo`

  #### Declaration

  `void `semanticTypeInfo`(Scope* `sc`, Type `t`);`

  Request additional semantic analysis for TypeInfo generation.

  #### Parameters

  `Scope* `sc`` | context
  `Type `t`` | type that TypeInfo is being generated for

- `StructDeclaration`

  #### Declaration

  `class `StructDeclaration`: dmd.aggregate.AggregateDeclaration;`

  All `struct` declarations are an instance of this.

  - `fit`

    #### Declaration

    `final bool `fit`(ref const Loc `loc`, Scope* `sc`, Expressions* `elements`, Type `stype`);`

    Fit `elements`[] to the corresponding types of the struct's fields.

    #### Parameters

    `Loc `loc`` | location to use for error messages
    `Scope* `sc`` | context
    `Expressions* `elements`` | explicit arguments used to construct object
    `Type `stype`` | the constructed object type.

    #### Return Value

    `false` if any errors occur, otherwise `true` and `elements`[] are rewritten for the output.

  - `isPOD`

    #### Declaration

    `final bool `isPOD`();`

    Determine if struct is POD (Plain Old Data).

    #### Discussion

    POD is defined as:

    1. not nested
    2. no postblits, destructors, or assignment operators
    3. no `ref` fields or fields that are themselves non-POD
    The idea being these are compatible with C structs.

    #### Return Value

    `true` if struct is POD

- `UnionDeclaration`

  #### Declaration

  `class `UnionDeclaration`: dmd.dstruct.StructDeclaration;`

  Unions are a variation on structs.