std::meta::is_defaulted

 

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Member accessibility queries is_accessible has_inaccessible_nonstatic_   data_members has_inaccessible_bases has_inaccessible_subobjects      Scope identification current_function current_class current_namespace Reflection member queries members_of bases_of static_data_members_of nonstatic_data_members_of subobjects_of enumerators_of Annotation reflection annotations_of annotations_of_with_type Value extraction extract Reflection substitution reflection_range can_substitute substitute Expression result reflection reflect_constant reflect_object reflect_function Class definition generation data_member_options data_member_spec is_data_member_spec define_aggregate

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Defined in header <meta>
consteval bool is_defaulted( std::meta::info r );		(since C++26)

Returns true if r represents a defaulted function. Otherwise returns false.

Parameters

r

-

a reflection value

Return value

true if r represents a defaulted function; otherwise false.

Example

Run this code

#include <compare>
#include <meta>

struct Base
{
    bool operator==(const Base&) const;
    std::strong_ordering operator<=>(const Base&) const = delete;
};

bool Base::operator==(const Base&) const = default;

struct Derived : public Base
{
    std::strong_ordering operator<=>(const Derived&) const = default; // implicitly deleted
    // operator== is implicitly defaulted due to the defaulted definition of operator<=>
};

static_assert(std::meta::is_defaulted(^^Base::operator==));
static_assert(!std::meta::is_defaulted(^^Base::operator<=>));
static_assert(std::meta::is_defaulted(^^Derived::operator==));
static_assert(std::meta::is_defaulted(^^Derived::operator<=>));

int main() {}

See also

is_function (C++26)	checks if reflection represents a function (function)
is_user_provided (C++26)	checks if reflection represents a user-provided function (function)