c++ boost::posix_time::ptime default value

Question

I have a member variable in my class:

class Foo
{
// ...
private:
  boost::posix_time::ptime t;
}

I want to initialize it in the constructor to a well known value such that I know it hasn't been set by the program yet:

Foo::Foo()
   : t(NULL) // doesnt work
{}

But setting it to NULL doesn't work because its not a pointer.

How do I initialize boost::posix_time::ptime to a well known value?

Answer 1

The default constructor initializes it to boost::posix_time::not_a_date_time. There is a member function to check for that t.is_not_a_date_time(). For more info see the docs.

#include <iostream>
#include <boost/date_time/posix_time/posix_time.hpp>

class Foo
{
public:
  boost::posix_time::ptime t;
  Foo() : t() {}
};

int main()
{
  Foo foo;
  std::cout << std::boolalpha
            << foo.t.is_not_a_date_time() << '\n';
}

Demo on Wandbox