va_start

 

C++

Lenguaje

Cabeceras

Conceptos

Biblioteca de utilidades

Biblioteca de cadenas

Biblioteca de contenedores

Biblioteca de algoritmos

Biblioteca de iteradores

Biblioteca numérica

Biblioteca de entrada/salida

Biblioteca de localización

Biblioteca de expresiones regulares (C++11)

Biblioteca de operaciones atómicas (C++11)

Biblioteca de hilos/subprocesos (C++11)

 

Utilidades de la biblioteca

Escriba apoyo (basic types, RTTI, type traits)

Gestión de memoria dinámica

Gestión de errores

Programa de servicios públicos

Funciones variadic

Fecha y hora

Objetos Function

initializer_list (C++11)

bitset

hash (C++11)

Operadores relacionales 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>=

Pares y tuplas 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)

Cambiar, hacia adelante y mover 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)

 

Funciones variadic

va_start

va_arg

va_copy

va_end

va_list

 

Definido en la cabecera <cstdarg>

void va_start(va_list ap, parm_n);

La macro va_start permite el acceso a los argumentos de variable tras el argumento con nombre parm_n .

Original:

The va_start macro enables access to the variable arguments following the named argument parm_n.

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You can help to correct and verify the translation. Click here for instructions.

va_start es conveniente recurrir a una instancia de un objeto válido va_list ap antes de cualquier llamada a va_arg .

Original:

va_start should be invoked with an instance to a valid va_list object ap before any calls to va_arg.

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Parámetros

ap	-	una instancia del tipo de va_list Original: an instance of the va_list type The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
parm_n	-	el parámetro llamado anterior a la primera parámetro variable Original: the named parameter preceding the first variable parameter The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.

Ampliado valor

(Ninguno)

Original:

(none)

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Ejemplo

#include <iostream>
#include <cstdarg>
 
int add_nums(int count, ...) 
{
    int result = 0;
    va_list args;
    va_start(args, count);
    for (int i = 0; i < count; ++i) {
        result += va_arg(args, int);
    }
    return result;
}
 
int main() 
{
    std::cout << add_nums(4, 25, 25, 50, 50) << '\n';
}

Salida:

150

Ver también

va_arg	accede a la función siguiente argumento variadic Original: accesses the next variadic function argument The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (macro de función)
va_end	termina recorrido de los argumentos de la función variadic Original: ends traversal of the variadic function arguments The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (macro de función)