std::istreambuf_iterator
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Definido no cabeçalho <iterator> | ||
template<class CharT, class Traits =std::char_traits<CharT>> class istreambuf_iterator :publicstd::iterator<std::input_iterator_tag, | ||
std::istreambuf_iterator é um iterador de entrada de passagem única, que lê os caracteres sucessivos a partir do objecto std::basic_streambuf para o qual foi construído. A operação de leitura actual é executada quando o iterador é incrementado, e não quando é dereferenced. O primeiro caractere pode ser lido quando o iterador é construído ou quando o dereferencing primeiro é feito. Caso contrário, dereferencing só retorna uma cópia do personagem mais recentemente li.Original:
std::istreambuf_iterator is a single-pass input iterator that reads successive characters from the std::basic_streambuf object for which it was constructed. The actual read operation is performed when the iterator is incremented, not when it is dereferenced. The first character may be read when the iterator is constructed or when the first dereferencing is done. Otherwise, dereferencing only returns a copy of the most recently read character.The text has been machine-translated via Google Translate.
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O padrão construído
std::istreambuf_iterator é conhecido como o fim-de-fluxo iterador. Quando um std::istreambuf_iterator válido atinge o final do fluxo de base, torna-se igual ao iterador fim-de-fluxo. Dereferencing ou incrementá-lo ainda mais invoca comportamento indefinido.Original:
The default-constructed
std::istreambuf_iterator is known as the end-of-stream iterator. When a valid std::istreambuf_iterator reaches the end of the underlying stream, it becomes equal to the end-of-stream iterator. Dereferencing or incrementing it further invokes undefined behavior.The text has been machine-translated via Google Translate.
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std::istreambuf_iterator tem um construtor de cópia trivial, um construtor padrão constexpr, e um destruidor trivial.Original:
std::istreambuf_iterator has a trivial copy constructor, a constexpr default constructor, and a trivial destructor.The text has been machine-translated via Google Translate.
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Índice |
[editar]Tipos de membro
Tipo de membro Original: Member type The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. | Definition |
char_type | CharT |
traits_type | Traits |
int_type | typename traits::int_type |
streambuf_type | std::basic_streambuf<CharT, Traits> |
istream_type | std::basic_istream<CharT, Traits> |
| Esta seção está incompleta Motivo: the proxy member type |
[editar]Funções de membro
constrói um novo istreambuf_iterator Original: constructs a new istreambuf_iterator The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (função pública membro) | |
(destructor) (declarada implicitamente) | destructs an istreambuf_iterator (função pública membro) |
(desde C++11) | obtém uma cópia do atual character accesses um membro do personagem atual, se CharT tem membros Original: obtains a copy of the current character accesses a member of the current character, if CharT has members The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (função pública membro) |
avança a istreambuf_iterator Original: advances the istreambuf_iterator The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (função pública membro) | |
se ambos os testes são istreambuf_iterators fim-de-stream ou se ambos são válidos Original: tests if both istreambuf_iterators are end-of-stream or if both are valid The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (função pública membro) | |
[editar]Não-membros funções
compara dois istreambuf_iterators Original: compares two istreambuf_iterators The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (modelo de função) | |
Herdado de std::iterator
Member types
Tipo de membro Original: Member 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 | CharT |
difference_type | Traits::off_type |
pointer | /* unspecified, usually CharT* */ |
reference | CharT |
iterator_category | std::input_iterator_tag |
[editar]Exemplo
#include <vector>#include <sstream>#include <iostream>#include <iterator>int main(){// typical use case: an input stream represented as a pair of iteratorsstd::istringstream in("Hello, world");std::vector<char> v((std::istreambuf_iterator<char>(in)), std::istreambuf_iterator<char>());std::cout<<"v has "<< v.size()<<" bytes. "; v.push_back('\0');std::cout<<"it holds \""<<&v[0]<<"\"\n"; // demonstration of the single-pass naturestd::istringstream s("abc"); std::istreambuf_iterator<char> i1(s), i2(s);std::cout<<"i1 returns "<<*i1 <<'\n'<<"i2 returns "<<*i2 <<'\n';++i1;std::cout<<"after incrementing i1, but not i2\n"<<"i1 returns "<<*i1 <<'\n'<<"i2 returns "<<*i2 <<'\n';++i2;// this makes the apparent value of *i2 to jump from 'a' to 'c'std::cout<<"after incrementing i2, but not i1\n"<<"i1 returns "<<*i1 <<'\n'<<"i2 returns "<<*i2 <<'\n'; }
Saída:
v has 12 bytes. it holds "Hello, world" i1 returns a i2 returns a after incrementing i1, but not i2 i1 returns b i2 returns a after incrementing i2, but not i1 i1 returns b i2 returns c
[editar]Veja também
iterador de saída que escreve para std::basic_streambuf Original: output iterator that writes to std::basic_streambuf The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (modelo de classe) | |
iterador de entrada que lê std::basic_istream Original: input iterator that reads from std::basic_istream The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (modelo de classe) | |
