bsl::enable_if

Synopsis

Declared in <bslmf_enableif.h>

template<
    bool t_COND,
    class t_TYPE = void>
struct enable_if;

Type Aliases

Name	Description
`type`	This `typedef` is an alias to the (template parameter) `t_TYPE`.

Specializations

Name Description

enable_if<true> This struct template implements the enable_if meta-function defined in the C++11 standard [meta.trans.ptr]. This struct template 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.

enable_if<false, t_TYPE> This partial specialization of enable_if, for when the (template parameter) t_COND is false, guarantees that no typedef type is supplied. Note that this class definition is intentionally empty.

Name	Description
`enable_if<true>`	This `struct` template implements the `enable_if` meta-function defined in the C++11 standard [meta.trans.ptr]. This `struct` template 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`.
`enable_if<false, t_TYPE>`	This partial specialization of `enable_if`, for when the (template parameter) `t_COND` is `false`, guarantees that no `typedef` `type` is supplied. Note that this class definition is intentionally empty.