How to set inherited C++ class/struct variables in single declaration

Is there a method I can use to be able to declare a new object w/ inherited variables with a single line of code? Example:

#include <iostream>

using namespace std;

struct item_t {
    string name开发者_Go百科;
    string desc;
    double weight;
};

struct hat_t : item_t
{
    string material;
    double size;
};

int main () 
{
    hat_t fedora; // declaring individually works fine
    fedora.name = "Fedora";
    fedora.size = 7.5;

    // this is also OK
    item_t hammer = {"Hammer", "Used to hit things", 6.25}; 

    // this is NOT OK - is there a way to make this work?
    hat_t cowboy = {"Cowboy Hat", "10 gallon hat", 4.5, "straw", 6.5}; 

    return 0;
}

Classes with inheritance are not POD and therefore are definitely not aggregates. If you are not using virtual functions, prefer composition to inheritance.

struct item_t {
    string name;
    string desc;
    double weight;
};

struct hat_t
{
    item_t item;
    string material;
    double size;
};

int main () 
{
    // this is also OK
    item_t hammer = {"Hammer", "Used to hit things", 6.25}; 

    // this is now valid
    hat_t cowboy = {"Cowboy Hat", "10 gallon hat", 4.5, "straw", 6.5}; 

    return 0;
}

I believe having base classes prevents the aggregate initialization syntax in C++03. C++0x has more general initialization using braces, and so it is more likely to work there.

Can you maybe just use a constructor?

struct item_t {
item_t(string nameInput, string descInput, double weightInput):
name(nameInput),
desc(descInput),
weight(weightInput)
{}

string name;
string desc;
double weight;
};

struct hat_t : item_t
{
    hat_t(string materinInput,d double sizeInput string nameInput, string descInput, double weightInput) :
    material(materialInput), size(size), item_t(nameInput, descInput, weightInput)
{}

string material;
double size;
};

then you can just call the constructor you want.