BloombergLP::bslstl::Optional_ConstructsFromType

Metafunction detecting constructibility from a non-optional type.

Synopsis

Declared in <bslstl_optional.h>

template<
    class t_TYPE,
    class t_ANY_TYPE>
struct Optional_ConstructsFromType
    : bsl::integral_constant<bool, !bslmf::IsAccessibleBaseOf<bsl::optional<t_TYPE>, typename bsl::remove_cvref<t_ANY_TYPE>::type>::value && !bsl::is_same<typename bsl::remove_cvref<t_ANY_TYPE>::type, bsl::nullopt_t>::value && !bsl::is_same<typename bsl::remove_cvref<t_ANY_TYPE>::type, bsl::in_place_t>::value && !bsl::is_same<typename bsl::remove_cvref<t_ANY_TYPE>::type, bsl::allocator_arg_t>::value && std::is_constructible<t_TYPE, t_ANY_TYPE>::value>

Description

This metafunction is derived from bsl::true_type if t_ANY_TYPE is not derived from bsl::optional<t_TYPE>, t_ANY_TYPE is not a tag type, and t_TYPE is constructible from t_ANY_TYPE.

Base Classes

NameDescription
bsl::integral_constant<bool, !bslmf::IsAccessibleBaseOf<bsl::optional<t_TYPE>, typename bsl::remove_cvref<t_ANY_TYPE>::type>::value && !bsl::is_same<typename bsl::remove_cvref<t_ANY_TYPE>::type, bsl::nullopt_t>::value && !bsl::is_same<typename bsl::remove_cvref<t_ANY_TYPE>::type, bsl::in_place_t>::value && !bsl::is_same<typename bsl::remove_cvref<t_ANY_TYPE>::type, bsl::allocator_arg_t>::value && std::is_constructible<t_TYPE, t_ANY_TYPE>::value>Metafunction representing a compile-time constant of the specified (template parameter) t_TYPE with the specified (template parameter) t_VALUE.

Type Aliases

NameDescription
type Alias for this integral_constant specialization.
value_type Alias for the (template parameter) t_TYPE.

Member Functions

NameDescription
operator() Return a copy of the template argument t_VALUE.
operator t_TYPE Return a copy of the template argument t_VALUE.

Static Data Members

NameDescription
value The compile-time constant value of this metafunction.