Passing inline double array as method argument

问题

Consider method

functionA (double[] arg)

I want to pass a double array inline, like

functionA({1.9,2.8})

and not create an array first and then pass it, like

double var[] = {1.0,2.0};
functionA(var);

Is this possible with C++? Sounds simple, but I could not find a hint anyway concerning my question which made me suspicious :).

回答1:

You can do this with std::initializer_list<>

#include<vector>

void foo(const std::initializer_list<double>& d)
{ }

int main()
{
    foo({1.0, 2.0});
    return 0;
}

Which compiles and works for me under g++ with -std=c++0x specified.

回答2:

This works with c++0x

void functionA(double* arg){
   //functionA
}

int main(){
    functionA(new double[2]{1.0, 2.0});
    //other code
    return 0;
}

Although you need to make sure that the memory allocated by new is deleted in the functionA(), failing which you there will be a memory leak!

回答3:

You can do it in C++11 using std::initializer_list.

void fun(std::initializer_list<double>);
// ...
fun({ 1., 2. });

You can't do it in C++03 (or it will involve enough boilerplate it won't be feasible).

来源：https://stackoverflow.com/questions/8739358/passing-inline-double-array-as-method-argument