How to initialize specific members of a C-struct in C++ - c++

Question

I am writing a C++ struct which contains a C-struct. The C-struct is included by other .c files, so I cannot change it to C++.
I want to make sure that every member is of the c++ struct is initialized.
So I have used in-class initialization and constructor initilizer where needed:
struct CppStruct
{
CStruct pod {}; // initialize all members to 0
int i = 0;
double d = 0.0;
CppStruct()
{ }
CppStruct(int another_val)
: i(another_val)
{ }
};
This initializes all the members of the CStruct to zeroes.
Zeroes are fine for most members of the c-struct,
but unfortunately, it also contains a C-enum whithout a zero-value:
// C-header
enum Color { // no '0' entries here!
red = 1,
yellow = 2;
};
struct CStruct { // this struct can potentially contain a lot of members
int i;
int j;
Color col;
int m;
int n;
};
The only way I have found to write the constructor is this, but this theoretically sets the pod.col member twice:
CppStruct()
{ pod.col = Color::red; }
CppStruct(int another_val)
: i(another_val)
{ pod.col = Color::red; }
Is there anyway I can override the initialization of selected members of the pod, without having to specify all its members?
e.g. I tried this but it does not compile:
CppStruct() : pod.col(Color::red) {}
The following is legal, but I want to avoid it,
in case the CStruct is changed/shuffled by another colleague:
CppStruct() : pod{0,0,Color::red,0,0} {}

Answer 1

The best way I think is to just overwrite the col value inside the constructor, don't worry about multiple initializations, as it's just an enum, not a massive object, so the performance difference is somewhat nothing (unless you are really desperate for performance).
A quick and dirty way to achieve initialization the way you wanted is to create a static function that would return a default CStruct like that:
struct CppStruct
{
CStruct pod {}; // initialize all members to 0
int i = 0;
double d = 0.0;
CppStruct()
: pod(_get_default_pod())
{ }
CppStruct(int another_val)
: i(another_val), pod(_get_default_pod())
{ }
private:
static inline CStruct _get_default_pod() {
CStruct pod {};
pod.col = Color::red;
return pod;
};
};