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Question

This question regards any C++ plain-old data definition in which there is a constructor that takes all data members as parameters and initializes them. The only reason for this over extended initializer lists is to prevent the error of only specifying part of the structure.

Here is the typical way to write such a struct:

struct Struct {
    A a;
    B b;
    C c;
    Struct(A a, B b, C c) : a(a) , b(b), c(c) {}
};

It's worth observing that the type of each member is written twice, and the name four times. In practice, this means the code for such structs is rather compressible. Is there a shorter way to write this struct in C++?

Answer 1

If your struct doesn't contain any pointer, you can use aggregate initializer in C++11.

#include <iostream>
using namespace std;

struct xxx {
    int a, b, c;
};

int main() {
    // your code goes here
    xxx x{1,2,3};
    cout << x.a << x.b << x.c;
    return 0;
}

Answer 2

Interesting question. I don't think there is a shorter way to write it, especially here where most of the names are one letter ;)

In general, C++ type definitions tend to be highly repetitive. You have to repeat the name of the type for all constructors and the destructor, for instance. Unfortunately, I think the only solution is to have tools generate the code for you.

Answer 3

In some cases, you might find useful to use std::par<A, B> , or std::tuple<A, B, C> .

For example:

std::tuple<A, B, C> t = std::make_tuple(a, b, c);

May be this will work for you better in some cases.