Metafunction that defines type to be the specified t_FALLBACK type unless t_FALLBACK is bslmf::Nil.
Declared in <bslmf_resulttype.h>
template<class t_FALLBACK>
struct ResultType_Fallback;| Name | Description |
|---|---|
type | The fallback type, unless t_FALLBACK is bslmf::Nil. |
| Name | Description |
|---|---|
ResultType_Fallback<bslmf::Nil> | Specialization of ResultType_Fallback that does not define type if bslmf::Nil is specified as the fallback parameter. |
| Name | Description |
|---|---|
ResultType_BdeIdiom | Metafunction to detect the BDE ResultType idiom as part of the implementation of bslmf::ResultType. This struct is instantiated when t_FUNC::result_type doesn't exist. This primary template is matched when t_FUNC::ResultType also does not exist. The t_FALLBACK type, if any, is produced. |