std::is_constructible, std::is_trivially_constructible, std::is_nothrow_constructible

 

C++

Linguaggio

Concetti

Libreria di Utilità

Stringhe

Contenitori

Algoritmi

Iteratori

Libreria matematca

Input/output

Localizzazione

Espressioni regolari(C++11)

Operazioni atomicche(C++11)

Multithreading(C++11)

 

Utilità libreria

Tipo di supporto (basic types, RTTI, type traits)

Gestione della memoria dinamica

La gestione degli errori

Programma di utilità

Funzioni variadic

Data e ora

Funzione oggetti

initializer_list (C++11)

bitset

hash (C++11)

Gli operatori relazionali Original: Relational operators The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.

rel_ops::operator!= rel_ops::operator> rel_ops::operator<= rel_ops::operator>=

Coppie e tuple Original: Pairs and tuples The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.

pair

tuple (C++11)

piecewise_construct_t (C++11)

piecewise_construct (C++11)

Swap, in avanti e spostare Original: Swap, forward and move The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.

swap

forward (C++11)

move (C++11)

move_if_noexcept (C++11)

declval (C++11)

 

Tipo di supporto

Tipi base Original: Basic types The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
Tipi fondamentali
Larghezza fissa interi tipi(C++11)
ptrdiff_t size_t max_align_t (C++11)	nullptr_t (C++11) offsetof NULL
Limiti numerici Original: Numeric limits The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
numeric_limits
C numerico limita interfaccia
Informazioni sul tipo di runtime Original: Runtime type information The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
type_info type_index (C++11)	bad_typeid bad_cast
Tipo tratti Original: Type traits The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
Categorie di tipo primario Original: Primary type categories The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
is_void (C++11) is_array (C++11) is_pointer (C++11) is_enum (C++11) is_union (C++11) is_class (C++11) is_function (C++11)	is_object (C++11) is_scalar (C++11) is_compound (C++11) is_integral (C++11) is_floating_point (C++11) is_fundamental (C++11) is_arithmetic (C++11)
is_reference (C++11)
is_lvalue_reference (C++11)
is_rvalue_reference (C++11)
is_member_pointer (C++11)
is_member_object_pointer (C++11)
is_member_function_pointer (C++11)

Proprietà del tipo Original: Type properties The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
is_const (C++11) is_volatile (C++11) is_pod (C++11) is_empty (C++11) is_polymorphic (C++11) is_abstract (C++11)	is_trivial (C++11) is_trivially_copyable (C++11) is_standard_layout (C++11) is_literal_type (C++11) is_signed (C++11) is_unsigned (C++11)

Operazioni supportate Original: Supported operations The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
is_constructible is_trivially_constructible is_nothrow_constructible (C++11) (C++11) (C++11)
is_default_constructible is_trivially_default_constructible is_nothrow_default_constructible (C++11) (C++11) (C++11)
is_copy_constructible is_trivially_copy_constructible is_nothrow_copy_constructible (C++11) (C++11) (C++11)
is_move_constructible is_trivially_move_constructible is_nothrow_move_constructible (C++11) (C++11) (C++11)
is_assignable is_trivially_assignable is_nothrow_assignable (C++11) (C++11) (C++11)
is_copy_assignable is_trivially_copy_assignable is_nothrow_copy_assignable (C++11) (C++11) (C++11)
is_move_assignable is_trivially_move_assignable is_nothrow_move_assignable (C++11) (C++11) (C++11)
is_destructible is_trivially_destructible is_nothrow_destructible (C++11) (C++11) (C++11)
has_virtual_destructor (C++11)
I rapporti e le query di proprietà Original: Relationships and property queries The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
is_same (C++11) is_base_of (C++11) is_convertible (C++11)	alignment_of (C++11) rank (C++11) extent (C++11)
Tipo modifiche Original: Type modifications The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
remove_cv remove_const remove_volatile (C++11) (C++11) (C++11) add_cv add_const add_volatile (C++11) (C++11) (C++11) make_signed (C++11) make_unsigned (C++11)	remove_reference (C++11) add_lvalue_reference add_rvalue_reference (C++11) (C++11) remove_pointer (C++11) add_pointer (C++11) remove_extent (C++11) remove_all_extents (C++11)
Tipo di trasformazioni Original: Type transformations The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
aligned_storage (C++11) aligned_union (C++11) decay (C++11) enable_if (C++11)	conditional (C++11) common_type (C++11) underlying_type (C++11) result_of (C++11)
Digitare costanti tratto Original: Type trait constants The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
integral_constant (C++11)

 

Elemento definito nell'header <type_traits>
template<class T, class... Args> struct is_constructible;	(1)	(dal C++11)
template<class T, class... Args> struct is_trivially_constructible;	(2)	(dal C++11)
template<class T, class... Args> struct is_nothrow_constructible;	(3)	(dal C++11)

1)

Se il T obj(arg1, arg2, ... argN); espressione è ben formato, dato riferimenti rvalue a Args... come argomenti, fornisce l'elemento costante valuetrue uguali. Per qualsiasi altro tipo, è valuefalse.

Original:

If the expression T obj(arg1, arg2, ... argN); is well-formed, given rvalue references to Args... as arguments, provides the member constant value equal true. For any other type, value is false.

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2)

uguale a 1), ma l'espressione di costruzione non richiede qualsiasi operazione che non è banale.

Original:

same as 1), but the constructor expression does not call any operation that is not trivial.

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3)

uguale a 1), ma l'espressione costruttore è noexcept.

Original:

same as 1), but the constructor expression is noexcept.

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Inherited from std::integral_constant

Member constants

value [statico]	true se T is constructible from Args... , false altrimenti Original: true if T is constructible from Args... , false otherwise The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (pubblico membro statico costante)

Member functions

operator bool	converte l'oggetto in bool, restituisce value Original: converts the object to bool, returns value The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (metodo pubblico)

Member types

Tipo Original: Type The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.	Definition
value_type	bool
type	std::integral_constant<bool, value>

Esempio

#include <iostream>#include <type_traits>   class Foo {int v1;double v2;public: Foo(int n): v1(n), v2(){} Foo(int n, double f)noexcept: v1(n), v2(f){}};   int main(){std::cout<<"Foo is ...\n"<<std::boolalpha<<"\tTrivially-constructible from const Foo&? "<< std::is_trivially_constructible<Foo, const Foo&>::value<<'\n'<<"\tTrivially-constructible from int? "<< std::is_trivially_constructible<Foo, int>::value<<'\n'<<"\tConstructible from int? "<< std::is_constructible<Foo, int>::value<<'\n'<<"\tNothrow-constructible from int? "<< std::is_nothrow_constructible<Foo, int>::value<<'\n'<<"\tNothrow-constructible from int and double? "<< std::is_nothrow_constructible<Foo, int, double>::value<<'\n';}

Output:

Foo is ... Trivially-constructible from const Foo&? true Trivially-constructible from int? false Constructible from int? true Nothrow-constructible from int? false Nothrow-constructible from int and double? true

Vedi anche

is_default_constructible is_trivially_default_constructible is_nothrow_default_constructible (C++11) (C++11) (C++11)	Verifica se un tipo ha un costruttore di default Original: checks if a type has a default constructor The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (classe template)
is_copy_constructible is_trivially_copy_constructible is_nothrow_copy_constructible (C++11) (C++11) (C++11)	Verifica se un tipo ha un costruttore di copia Original: checks if a type has a copy constructor The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (classe template)
is_move_constructible is_trivially_move_constructible is_nothrow_move_constructible (C++11) (C++11) (C++11)	Verifica se un tipo ha un costruttore mossa Original: checks if a type has a move constructor The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (classe template)
uses_allocator (C++11)	controlla se il tipo specificato supporta usi-allocatore di costruzione Original: checks if the specified type supports uses-allocator construction The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (classe template)