This struct is a component-private meta-function. Do not use. This meta-function checks whether the template parameter type VISITOR has the member ResultType defined using "SFINAE" (Substitution Failure Is Not An Error). A value of true indicates VISITOR::ResultType exists, and false otherwise.
Declared in <bdlb_variant.h>
template<class VISITOR>
struct Variant_ReturnValueHelper
: bsl::integral_constant<bool, sizeof (Variant_ReturnValueHelper_Matcher::match<VISITOR>(0)) == sizeof(Variant_ReturnValueHelper_YesType)>| Name | Description |
|---|---|
bsl::integral_constant<bool, sizeof (Variant_ReturnValueHelper_Matcher::match<VISITOR>(0)) == sizeof(Variant_ReturnValueHelper_YesType)> | Metafunction representing a compile-time constant of the specified (template parameter) t_TYPE with the specified (template parameter) t_VALUE. |
| Name | Description |
|---|---|
type | Alias for this integral_constant specialization. |
value_type |
| Name | Description |
|---|---|
operator() | Return a copy of the template argument t_VALUE. |
operator value_type |
| Name |
|---|
value |