BloombergLP::bslstl::Variant_OverloadSetImp

This component-private metafunction computes an overload set consisting of one function, named candidate, for each type in (template parameters) t_HEAD, t_TAIL..., having one parameter of that type. Each such function participates in overload resolution only when std::declval<t_SRC>() is convertible to the alternative without narrowing, and returns bsl::integral_constant<t_INDEX + i>, where i is the zero-based index of the corresponding alternative. Note that a type that occurs multiple times in t_HEAD, t_TAIL... (possibly with varying cv-qualifications) will only result in the generation of a single candidate. This implementation relies on expression SFINAE, decltype, std::declval, and P1957R2; since these features are not available in C++03, the C++03 version requires an exact match modulo cv-qualification.

Synopsis

Declared in <bslstl_variant.h>

template<
    class t_SRC,
    size_t t_INDEX,
    class t_HEAD,
    class... t_TAIL>
struct Variant_OverloadSetImp
    : Variant_OverloadSetImp<t_SRC, t_INDEX + 1, t_TAIL...>

Base Classes

Name Description

Variant_OverloadSetImp<t_SRC, t_INDEX + 1, t_TAIL...> This component-private metafunction computes an overload set consisting of one function, named candidate, for each type in (template parameters) t_HEAD, t_TAIL..., having one parameter of that type. Each such function participates in overload resolution only when std::declval<t_SRC>() is convertible to the alternative without narrowing, and returns bsl::integral_constant<t_INDEX + i>, where i is the zero-based index of the corresponding alternative. Note that a type that occurs multiple times in t_HEAD, t_TAIL... (possibly with varying cv-qualifications) will only result in the generation of a single candidate. This implementation relies on expression SFINAE, decltype, std::declval, and P1957R2; since these features are not available in C++03, the C++03 version requires an exact match modulo cv-qualification.

Name	Description
`Variant_OverloadSetImp<t_SRC, t_INDEX + 1, t_TAIL...>`	This component-private metafunction computes an overload set consisting of one function, named `candidate`, for each type in (template parameters) `t_HEAD, t_TAIL...`, having one parameter of that type. Each such function participates in overload resolution only when `std::declval<t_SRC>()` is convertible to the alternative without narrowing, and returns `bsl::integral_constant<t_INDEX + i>`, where `i` is the zero-based index of the corresponding alternative. Note that a type that occurs multiple times in `t_HEAD, t_TAIL...` (possibly with varying cv-qualifications) will only result in the generation of a single candidate. This implementation relies on expression SFINAE, `decltype`, `std::declval`, and P1957R2; since these features are not available in C++03, the C++03 version requires an exact match modulo cv-qualification.

Static Member Functions

Name	Description
`candidate`	Overload candidate selecting alternative `t_INDEX` for source type `t_SRC`.

Using Declarations

Name
`candidate`

Specializations

Name
`Variant_OverloadSetImp<t_SRC, t_INDEX, t_HEAD>`

Derived Classes

Name Description

Variant_OverloadSetImp This component-private metafunction computes an overload set consisting of one function, named candidate, for each type in (template parameters) t_HEAD, t_TAIL..., having one parameter of that type. Each such function participates in overload resolution only when std::declval<t_SRC>() is convertible to the alternative without narrowing, and returns bsl::integral_constant<t_INDEX + i>, where i is the zero-based index of the corresponding alternative. Note that a type that occurs multiple times in t_HEAD, t_TAIL... (possibly with varying cv-qualifications) will only result in the generation of a single candidate. This implementation relies on expression SFINAE, decltype, std::declval, and P1957R2; since these features are not available in C++03, the C++03 version requires an exact match modulo cv-qualification.

Name	Description
`Variant_OverloadSetImp`	This component-private metafunction computes an overload set consisting of one function, named `candidate`, for each type in (template parameters) `t_HEAD, t_TAIL...`, having one parameter of that type. Each such function participates in overload resolution only when `std::declval<t_SRC>()` is convertible to the alternative without narrowing, and returns `bsl::integral_constant<t_INDEX + i>`, where `i` is the zero-based index of the corresponding alternative. Note that a type that occurs multiple times in `t_HEAD, t_TAIL...` (possibly with varying cv-qualifications) will only result in the generation of a single candidate. This implementation relies on expression SFINAE, `decltype`, `std::declval`, and P1957R2; since these features are not available in C++03, the C++03 version requires an exact match modulo cv-qualification.