C ++中可变数量的函数参数

Question

So, in C the standard way is stdarg.h. But I'm looking to pull up something a bit like this:

template<int A>
class MyClass {
public:
    MyClass(...) {
        // fill each value of array with an argument.
    };

    virtual ~MyClass() { };
private:
    float array[A];
};

Obviously, the idea is not to have different constructions for every possible amount of arguments. Any suggestions, standard ways, whatsoever?

Thanks,

Julian.

Answer 1

In C++11 you can use an std::initializer_list constructor for this kind of scenario. That allows for this type of initialization:

MyClass<5> x{1,2,3,4,5};

although you have to define what happens when the dimensions do not match. But for these kinds of statically sized arrays, it is worth looking at std::array . These have a well defined behaviour when the dimensions of the initializer don't match their own.

Answer 2

you need to use initializer_list

explicit MyClass(std::initializer_list<T> list_args){
    // fill each value of array with an argument.
};

Answer 3

If you don't have access to C++11 initializer_lists you can just pass a vector.

MyClass(const std::vector& values) {
    //copy values into array
};

MyClass someClass( std::vector<int>(10,4) ); //adds 10x 4 to the vector