A little class like this one can be useful for classes where this is an issue:

//auto-initialize POD types as well as class types template struct auto_zero { T data; operator T&() {return data;} operator T const&() const {return data;}

auto_zero(T const& d) : data(d) {} auto_zero() : data() {} };

This is probably fairly similar to boost::value_initialized also. I've sometimes also found it convenient to partially specialize for pointers:

template struct auto_zero { T* data; operator T*&() {return data;} operator T* const&() const {return data;}

T& operator*() const {return *data;} T* operator->() const {return data;}

auto_zero(T *const d) : data(d) {} auto_zero() : data() {} };

Anyway the idea is, instead of

struct A { int i,j,k,l,m; A() : i(), j(), k(), l(), m() {} };

which can easily become a maintenance problem, you just do

struct A { auto_zero i,j,k,l,m; };

The automatic conversions make this completely transparent pretty much 99% of the time, occasionally you need an explicit cast, such as if you want to use one of the variables in a switch statement.

-Lewis