CODEWITHSUNDEEP
c++functionargumentsvariadic-functions
Karthik T
Karthik T

Reputation: 31962

How do to pass variable number of arguments to a function in c++ with no named parameters

I need to write a function which takes a variable number of arguements, its essentially a wrapper around a snprintf like function. I understand how to do this in general as shown in Passing variable number of arguments around.

How ever it appears that, atleast in C, we are required to pass one named parameter to the function before the variable arguments start( Why is void f(...) not allowed in C? ).

However the answers to the same questions say this is easily possible in C++. I was wondering how to achieve this, especially since the method for handling vararg functions seems to be the same as C(va_start, etc). Or are they referring to variadic templates?

So basically is it possible to write a variadic function with no named arguements, as shown below, and if so, how?

void f(...){
   ... 
}

p.s. I would like to do this with c++03 if possible.

Upvotes: 4

Views: 533

Answers (1)

AnT stands with Russia
AnT stands with Russia

Reputation: 320719

While C++ language allows writing functions whose parameter list consist only of ..., the language provides no means for accessing the arguments in functions declared with (...) parameter list.

Basically such functions in C++ exist for their behavior in overload resolution (... parameters match any parameter type). The body of such function will not have access to the arguments. If you see no uses for such functions, just don't use them.

Such functions are often used in non-executed context in some well-known template meta-programming techniques, in which case they don't even have to be defined - a mere declaration is sufficient.

Upvotes: 4

Related Questions