How to correctly initialize member variable of template type?

Question

suggest i have a template function like following:

template<class T> void doSomething() {     T a; // a is correctly initialized if T is a class with a default constructor     ... }; 

But variable a leaves uninitialized, if T is a primitive type. I can write T a(0), but this doesn't work if T is a class. Is there a way to initialize the variable in both cases (T == class, T == int, char, bool, ...)?

Answer 1

Like so:

T a{}; 

---

Pre-C++11, this was the simplest approximation:

T a = T(); 

But it requires T be copyable (though the copy is certainly going to be elided).

Answer 2

Class template field in C++11 has the same syntax:

template <class T> class A {   public:     A() {}     A(T v) : val(v) {}   private:     T val{}; };