std::tie
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<metanoindex/>
<tbody> </tbody>| Definido no cabeçalho <tuple>
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template< class... Types > tuple<Types&...> tie( Types&... args ); |
(desde C++11) | |
Cria uma tupla de referências lvalue aos seus argumentos ou instâncias de std::ignore.
Original:
Creates a tuple of lvalue references to its arguments or instances of std::ignore.
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
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Parâmetros
| args | - | zero ou mais argumentos lvalue para construir a tupla
Original: zero or more lvalue arguments to construct the tuple from The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. |
Valor de retorno
Um objeto que contém
std::tuple lvalue referenes.Original:
A
std::tuple object containing lvalue referenes.The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
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Exceções
Exemplo
std::tie pode ser utilizada para introduzir lexicographical comparação a uma estrutura ou a um tuplo descompactar:
Original:
std::tie can be used to introduce lexicographical comparison to a struct or to unpack a tuple:
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
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#include <iostream>
#include <string>
#include <set>
#include <tuple>
struct S {
int n;
std::string s;
float d;
bool operator<(const S& rhs) const
{
// compares n to rhs.n,
// then s to rhs.s,
// then d to rhs.d
return std::tie(n, s, d) < std::tie(rhs.n, rhs.s, rhs.d);
}
};
int main()
{
std::set<S> set_of_s; // S is LessThanComparable
S value{42, "Test", 3.14};
std::set<S>::iterator iter;
bool inserted;
// unpacks the return value of insert into iter and inserted
std::tie(iter, inserted) = set_of_s.insert(value);
if(inserted)
std::cout << "Value was inserted sucessfully\n";
}
Saída:
Value was inserted sucessfully
cria um objeto tuple do tipo definido pelo tipo de argumentoOriginal: creates a tuple object of the type defined by the argument typesThe text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (modelo de função) | |
cria um tuple de referências rvalueOriginal: creates a tuple of rvalue referencesThe text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (modelo de função) | |
cria um tuple pela concatenação de qualquer número de tuplasOriginal: creates a tuple by concatenating any number of tuplesThe text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (modelo de função) | |
espaço reservado para pular um elemento quando descompactar um tuple usando tie Original: placeholder to skip an element when unpacking a tuple using tie The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (constante) |