Default initialization in C++

Question

I was asking myself something this morning, and I can\'t find the words to properly \"google\" for it:

Lets say I have:

struct Foo
{
  int bar;
};

s         


        

Answer 1

For pod-types, the default initialization is zero-initialization.

Therefore:

Foo() : b() {} is the same as Foo() : b(0) {}

I can't find the respective part of the C++ standard, but if you skip the initializer completely, then POD types shouldn't be default-initialized (unlike non-POD types, which are).

Therefore in your case, only the third example is correctly initialized.