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    Returns a reflection that represents an array object whose elements are corresponding elements of {{tt|r}}.
    Returns a reflection that represents an array object whose elements are corresponding elements of {{tt|r}}.


    Let {{tt|T}} be {{c|ranges::range_value_t<R>}}.
    Let {{tt|T}} be {{c|ranges::range_value_t<R>}}.
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    ===Notes===
    ===Notes===
    As a template parameter object, the resulting object has static [[cpp/language/storage duration|storage duration]]. Ranges with [[cpp/language/template parameters#Template argument equivalence|template-argument-equivalent]] contents correspond to the same object.
    The resulting object is a [[cpp/language/objects#Address|potentially non-unique object]].
    The result of {{tt|std::meta::reflect_constant_array}} is suitable for use with {{ltt|cpp/meta/substitute|std::meta::substitute}}. If the caller wants a span of a static array, as opposite to a reflection value, {{ltt|cpp/meta/define_static_string|std::define_static_array}} is usually more suitable.
    The result of {{tt|std::meta::reflect_constant_array}} is suitable for use with {{ltt|cpp/meta/substitute|std::meta::substitute}}. If the caller wants a span of a static array, as opposite to a reflection value, {{ltt|cpp/meta/define_static_string|std::define_static_array}} is usually more suitable.


    Latest revision as of 14:03, 1 May 2026

     
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    Defined in header <meta> 
    template< ranges::input_range R >
consteval std::meta::info reflect_constant_array( R&& r );
    		(since C++26)

    Returns a reflection that represents an array object whose elements are corresponding elements of r.

    The resulting object is a template parameter object: it has static storage duration, and ranges with template-argument-equivalent contents correspond to the same object.

    If the size of r is not zero, the resulting array object is a potentially non-unique object.

    Let T be ranges::range_value_t<R>.

    The program is ill-formed if T is not a structural type, if std::is_constructible_v<T, ranges::range_reference_t<R>> is false, or if T does not satisfy copy_constructible.

    Parameters

    r - an input_range

    Return value

    If the size of r is not zero, a reflection that represents a template parameter object of type const T[N] (where N is the size of r). Each element of the template parameter object is initialized from the value or object represented by std::meta::reflect_constant(static_cast<T>(*it)), where it is an iterator to the corresponding element of r.

    Otherwise (the size of r is zero), a reflection that represents the template parameter object of type const std::array<T, 0> initialized with {}.

    Exceptions

    Throws any exception thrown by the evaluation of static_cast<T>(*it), or std::meta::exception if the evaluation of std::reflect_constant would exit via an exception.

    Notes

    The result of std::meta::reflect_constant_array is suitable for use with std::meta::substitute. If the caller wants a span of a static array, as opposite to a reflection value, std::define_static_array is usually more suitable.

    Example

    This section is incomplete
    Reason: no example

    See also

    (C++26)
    		 promotes compile-time array into static storage, returning a span of the static array
    (function template) [edit]
    (C++26)
    		 promotes a compile-time string to static storage, returning a reflection representing the static string
    (function template) [edit]
    (C++26)
    		 returns a reflection representing a value or object, suitable for use as a constant template argument
    (function template) [edit]