std::meta::is_implicit_lifetime_type

 

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Const-volatile modifications remove_const remove_volatile remove_cv add_const add_volatile add_cv Reference modifications remove_reference add_lvalue_reference add_rvalue_reference Sign modifications make_signed make_unsigned Array modifications remove_extent remove_all_extents Pointer modifications remove_pointer add_pointer Other transformations remove_cvref decay common_type common_reference underlying_type invoke_result unwrap_reference unwrap_ref_decay tuple_size tuple_element is_applicable_type is_nothrow_applicable_type apply_result variant_size variant_alternative type_order

 

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

Returns true if r represents an implicit-lifetime type. Otherwise returns false.

Parameters

r

-

a reflection value

Return value

true if r represents an implicit-lifetime type; otherwise false.

Exceptions

Throws std::meta::exception if r does not represent a type or type alias.

Example

Run this code

#include <cstddef>
#include <meta>

enum E { e };

struct S
{
    int x, y;
};

struct X
{
    X() {}
    ~X() = delete;
};

static_assert
(""
    and is_implicit_lifetime_type(^^int)            // arithmetic type is a scalar type
    and is_implicit_lifetime_type(^^const int)      // cv-qualified scalar type
    and is_implicit_lifetime_type(^^E)              // enumeration type is a scalar type
    and is_implicit_lifetime_type(^^int*)           // pointer type is a scalar type
    and is_implicit_lifetime_type(^^std::nullptr_t) // scalar type
    
    // S is an implicit-lifetime class: an aggregate without user-provided destructor
    and is_implicit_lifetime_type(^^S)
    
    and is_implicit_lifetime_type(^^int S::*) // pointer-to-member

    // X is not implicit-lifetime class due to deleted destructor
    and not is_implicit_lifetime_type(^^X)

    and is_implicit_lifetime_type(^^int[8])          // array type
    and is_implicit_lifetime_type(^^volatile int[8]) // cv-qualified array type
);

int main() {}

See also

is_scalar_type (C++26)	checks if reflected type is a scalar type (function)
is_array_type (C++26)	checks if reflected type is an array type (function)
is_aggregate_type (C++26)	checks if reflected type is an aggregate type (function)
start_lifetime_asstart_lifetime_as_array (C++23)	implicitly creates objects in given storage with the object representation reused (function template)
is_implicit_lifetime (C++23)	checks if a type is an implicit-lifetime type (class template)