Question

extern "C" {
    typedef struct Pair_s {
        char *first;
        char *second;
    } Pair;

    typedef struct PairOfPairs_s {
        Pair *first;
        Pair *second;
    } PairOfPairs;
}

Pair pairs[] = {
    {"foo", "bar"}, //this is fine
    {"bar", "baz"}
}; 

PairOfPairs pops[] = {
    {{"foo", "bar"}, {"bar", "baz"}}, //How can i create an equivalent of this NEATLY
    {&pairs[0], &pairs[1]} //this is not considered neat (imagine trying to read a list of 30 of these)
}; 

How can I achieve the above style declaration semantics?

Answer 1

In C++11 you could write:

PairOfPairs pops[] = {
    { new Pair{"a", "A"}, new Pair{"b", "B"} },
    { new Pair{"c", "C"}, new Pair{"d", "D"} },
    // the grouping braces are optional
};

Do note the implications of using the free store: objects allocated there are not destructed at the end of the execution of your program (like static objects are) or anytime else (without a corresponding delete). Probably not a concern in hosted implementations if Pair is a C struct and does not manage resources (and you always expected your program to use that memory until it exits).

edit: If you can’t use C++11 features, you can always create a helper function. Example:

static Pair* new_pair(const char* first, const char* second)
{
    Pair* pair = new Pair;
    pair->first = first;
    pair->second = second;
    return pair;
}