This struct template implements a meta-function that provides a typedef type that is an alias to the (template parameter) t_TYPE if the (template parameter) t_COND is true; otherwise, type is not provided. If t_TYPE is not specified, it is set to void. Note that this generic default template provides type for when t_COND is true; a template specialization is provided (below) that omits type for when t_COND is false.
Declared in <bslmf_enableif.h>
template<
bool t_COND,
class t_TYPE = void>
struct EnableIf;Also note that although this struct is functionally identical to bsl::enable_if, the use of bsl::enable_if should be preferred.
| Name | Description |
|---|---|
type | This typedef is an alias to the (template parameter) t_TYPE. |
| Name | Description |
|---|---|
EnableIf<false, t_TYPE> | This partial specialization of EnableIf, for when the (template parameter) t_COND is false, guarantees that no typedef type is supplied. Note that this class definition is intentionally empty. |