Theory questions for TDDD38 2016-08-17

1.
By returning a raw pointer, we will leave it up to the user of our function to deallocate the resource.
The problem here is of course that a raw pointer could also point to some static memory that cannot be
deallocated.

2.
a constexpr funciton is a function that the compiler can calculate at compile time to create constant values.
constexpr int foo(int n)
{
    return n+1;
}

The return value can be used where the compiler requires a constant expression, such as a template argument:
std::array<int, foo(3)> arr;

3.
struct Foo
{
    Foo(int a)
      : f_b{a}, f_a{f_b+2} {}

    int f_a;
    int f_b;
};
This might look correct, but the compiler will always initialize the members in declaration order which means
that f_a will be initialized first using a "random" (uninitialized) value of f_b before f_b is initialized.

4.
class X
{
    operator int();
};

5.
It has to be a template class that takes exactly two template arguments. One simple example is pair:
 pair<int,char>

It will not work for map (takes four arguments but have defaulted values)