Templated functions that accept a number of args

[high cape]

I’ve been getting familiar with templates and I understand them now but when I started looking at example code with templates functions, I’ve seen some where it seems like they are able to accept any number of arguments and I don’t think there creating overloads for versions that take 1 2 3 or 5+ args. How is this done?

[sand silo]

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[obsidian rune]

variadic template parameters

e.g. ```cpp
template<typename... Args>
void f(Args... args);

Args can be a pack of any number of types

hi kolio98

[lusty yoke]

... and the raw debugger can show you all the existing template instantiations in your program by politely asking info functions f

[lusty yoke]

go on

[lusty yoke]

For example, since C# doesn't have this feature, they do functions like this:

Func<T1,T2,T3,T4,T5,T6,T7,T8,T9,T10,T11,T12,T13,T14,T15,T16,TResult> Delegate

which is naive,

but C++ does:

template< class R, class... Args >
class function<R(Args...)>;

this

[obsidian rune]

this might be beyond their understanding, which is why I made a very simple example

[lusty yoke]

to view the raw templates here @high cape you can use:

template<typename... Args>
void f(Args... args)
{
    int num1 = 20;
}

int main()
{
    f(1, 4.5, "text", 0.0f, &main);
}

which shows:

<source>: In instantiation of 'void f(Args ...) [with Args = {int, double, const char*, float, int (*)()}]':
<source>:10:6:   required from here
   10 |     f(1, 4.5, "text", 0.0f, &main);
      |     ~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
<source>:5:9: error: unused variable 'num1' [-Werror=unused-variable]
    5 |     int num1 = 20;
      |         ^~~~
cc1plus: all warnings being treated as errors
Compiler returned: 1

and here the compiler warning shows the template types instantiated inside the function f