In computer science, an operator or function is variadic if it can take a varying number of arguments; that is, if its arity is not fixed.
Questions tagged [variadic]
668 questions
4
votes
1 answer
Pass nested types to a parent class without repeating yourself (DRY) in C++20
As shown in the example below, I need my Component struct to be able to access all the "fields" structs defined in a child struct. But I have some constraints:
The fields must be declared as nested types of the inheriting struct.
I cannot use any…
Renondedju
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4
votes
4 answers
How to get all parameters passed into a function, with their values?
I have a function
adebo.deepSearch = function(z, pi_0 = 0.3, families=list(), ... )
{
}
I want to capture all of the parameter names and values passed in by way of a function called grabFunctionParameters; e.g.,
adebo.deepSearch =…
mshaffer
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4
votes
1 answer
Swift Protocol with Variadic property
I'm trying to create Swift Protocol with Variadic property. According to the docs, it's possible to do it in a function:
func arithmeticMean(_ numbers: Double...) -> Double {
var total: Double = 0
for number in numbers {
total +=…
Roi Mulia
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4
votes
1 answer
template function pointers and lambdas
Hi I'm trying to sort out an issue with the following code:
template
using Func = void (*)(Args... args);
template
void do_test(Func f, Args&... args) {
for (int i = 0; i != 100; i++)
…
Joel Holdsworth
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4
votes
2 answers
swift combine declarative syntax
The declarative syntax of Swift Combine looks odd to me and it appears that there is a lot going on that is not visible.
For example the following code sample builds and runs in an Xcode playground:
[1, 2, 3]
.publisher
.map({ (val) in
…
bhartsb
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4
votes
1 answer
FFI in Chez Scheme for C functions with variadic arguments (varargs)
I want to write a FFI for printf function of C in Chez Scheme using foreign-procedure. But I cannot figure out what I should put as the signature, since the last argument in printf function is a variadic argument. Here's my code:
(import…
Reza Hajianpour
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0 answers
How to retrieve the type of a variadic template argument?
I cant find a way to define a type like this:
template
using hasSomeFunc = decltype(std::declval().SomeFunc(std::declval>(),…
Iñigo
- 97
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4
votes
3 answers
C++ template: cannot match the last template in variadic class template
I'm learning C++11 variadic template and created a template struct to calculate the max number of a given list and tried:
#include
#include
template
struct max: std::integral_constantb?…
bigtit
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4
votes
1 answer
How do I pass each element of a slice as a separate argument to a variadic C function?
I'm building a Redis Module in Rust. I've found some good examples, but I'm stuck when dealing with interfacing a C function that is supposed to accept variadic arguments.
The Redis Module C SDK has a function called RedisModule_Call which accepts…
stockholmux
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4
votes
2 answers
Passing arguments to another variadic function
Is there any way at all for this code to compile and work as intended without resorting to va_list stuff ?
#include
void fct(void)
{
std::cout << std::endl;
}
void fct(int index, int indexes...)
{
std::cout << index << ' ';
…
Pippin
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4
votes
4 answers
How to pass not variadic values to fmt::format?
I'm playing with the great fmt C++ library to format strings more gracefully.
And I'd like to pass a non-variable arguments list to fmt::format. It could be a std::vector, or std::string, or whatever, but it will always match the format string.
So…
Kyone
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4
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2 answers
Can using an array as the last named argument to a variadic function result in a buffer underrun?
I found this paragraph in the man page for stdarg.h:
Because the address of this parameter is used in the va_start() macro, it should not be declared as a register variable, or as a function or an array type.
So, register variable I understand,…
Shoblade X
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4
votes
2 answers
What is the appropriate way to retrieve the value of a C++ variadic template constant argument at position N?
I would like to know what is the correct way to retrieve the value of a variadic template constant argument at position N (N is known at compile time). For instance, let's say you have a template that receives a variadic number of function pointers…
pmjobin
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4
votes
1 answer
How to make template deduce return type of function with variadic arguments
Someone on stack overflow wrote an interesting way to capture a lambda or functor into your own class. I was trying to simplify it, and I think I got close but was having some trouble. Their example was:
// OT => Object Type
// RT => Return Type
//…
Zebrafish
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4
votes
2 answers
Creating POD with variable number of elems
I would like to have a type, that would be in effect POD but I would like to be able to specify how and which types are in it, for example:
template
struct POD
{
//here I would like to create depending on Args appropriate types as a…
There is nothing we can do
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