initializing struct on declaration

[philonto]

Code:

struct foo {
    char label[64];
    int state;
} bar[3] = { };

Will the above code ALWAYS initialize to 0 all objects:

bar[0].label
bar[0].state
bar[1].label
bar[1].state
bar[2].label
bar[2].state

Using gcc and g++, it does in my testing
But was wondering if it can be unsafe under some circumstances.

I even tried without = { } and it is still initialized to 0 for all objects!

[Cubbi]

Yes, aggregate initialization with all initializers omitted (which is what = { } is) guarantees that your members will be initialized to zeroes

http://en.cppreference.com/w/cpp/language/aggregate_initialization

I even tried without = { } and it is still initialized to 0 for all objects!

Without = { }, you are using default initialization, which is only guaranteed to zero them out if your object is static (or thread-local), e.g. if you're defining this at file scope.

http://en.cppreference.com/w/cpp/language/zero_initialization

[philonto]

Thank you for the references

[philonto]

One other question
when declared in header, what is the easiest way to initialize it in code?
For now I do using a void function called on program start.
wondering if there is an easier way to do it like for regular variables

[Cubbi]

wondering if there is an easier way to do it like for regular variables

variables of struct type are no different from variables of any other type.

struct foo {
    char label[64];
    int state;
};
int main()
{
    foo a;
    foo b = {};
    a.state=7;
}

[philonto]

yes, as I said, I am using a function already
the struct is in a header shared among many source files

So, I need to call a function to initialize it
Thanks