Espaços nominais
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NULL

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< cpp‎ | types

 
 
Biblioteca de utilitários
Digite apoio (basic types, RTTI, type traits)
Gerenciamento de memória dinâmica
De tratamento de erros
Utilidades do programa
Variadic funções
Data e hora
Objetos de função
initializer_list(C++11)
bitset
hash(C++11)
Os operadores relacionais
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Relational operators
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rel_ops::operator!=
rel_ops::operator>
rel_ops::operator<=
rel_ops::operator>=
Pares e tuplas
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Pairs and tuples
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pair
tuple(C++11)
piecewise_construct_t(C++11)
piecewise_construct(C++11)
Troque, avançar e avançar
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Swap, forward and move
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swap
forward(C++11)
move(C++11)
move_if_noexcept(C++11)
declval(C++11)
 
Digite apoio
Tipos básicos
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Basic types
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Tipos fundamentais
Tipos inteiros de largura fixos (C++11)
nullptr_t(C++11)
offsetof
NULL
Limites numéricos
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Numeric limits
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numeric_limits
C numérico limita interface
Informações de tipo de tempo de execução
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Runtime type information
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Características de tipo
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Type traits
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Principais categorias de tipo
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Primary type categories
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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)
Propriedades de tipo
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Type properties
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is_const(C++11)
is_volatile(C++11)
is_pod(C++11)
is_empty(C++11)
is_polymorphic(C++11)
is_abstract(C++11)
Operações apoiadas
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Supported operations
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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)
Relacionamentos e consultas de propriedade
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Relationships and property queries
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is_same(C++11)
is_base_of(C++11)
is_convertible(C++11)
alignment_of(C++11)
rank(C++11)
extent(C++11)
Tipo modificações
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Type modifications
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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)
Transformações tipo
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Type transformations
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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)
Digite constantes traço
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Type trait constants
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integral_constant(C++11)
 
Defined in header <cstddef>
Defined in header <cstring>
Defined in header <cwchar>
Defined in header <ctime>
Defined in header <clocale>
Defined in header <cstdio>
#define NULL /*implementation-defined*/
Define a constante ponteiro nulo, que é uma expressão integral prvalue constante do tipo inteiro que avalia a zero ou um prvalue de std::nullptr_t tipo. O ponteiro nulo constante pode ser convertidos implicitamente a qualquer tipo de ponteiro; resultados de conversão desse tipo no valor de ponteiro nulo do tipo. Se a constante de ponteiro nulo tem tipo inteiro, ele pode ser convertido para um tipo de prvalue std::nullptr_t.
Original:
Defines the null pointer constant, which is an integral constant expression prvalue of integer type that evaluates to zero or a prvalue of type std::nullptr_t. The null pointer constant may be convertidos implicitamente to any pointer type; such conversion results in the null pointer value of that type. If the null pointer constant has integer type, it may be converted to a prvalue of type std::nullptr_t.
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[editar] Possível implementação

#define NULL 0
//since C++11
#define NULL nullptr

[editar] Exemplo

#include <cstddef>
class S;
int main()
{
    int* p = NULL;
    int* p2 = static_cast<std::nullptr_t>(NULL);
    void(*f)(int) = NULL;
    int S::*mp = NULL;
    void(S::*mfp)(int) = NULL;
}


[editar] Veja também

nullptr
o ponteiro literal que especifica um valor nulo (C++11) ponteiro
Original:
the pointer literal which specifies a null pointer value (C++11)
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[edit]
(C++11)
o tipo de nullptr ponteiro nulo literal
Original:
the type of the null pointer literal nullptr
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(typedef) [edit]