On Mon, 17 Nov 2003 16:23:14 +0100, Michael Haubenwallner wrote
Hi,
I'm preparing my company's step from C to C++, and when i use boost::date_time::*, there's a great danger to make mistakes like this with boost-1.30.2:
#include
#include <iostream> #include
using namespace boost::posix_time; using namespace boost::gregorian;
int main() { time_t now = time(0);
try { ptime time(now); // mistake
cerr << to_simple_string(time) << endl; } catch (exception const& e) { cerr << "error: " << e.what() << endl; } }
The problem is that the time_t in this case is treated as a day-count from which a gregorian::date() is implicitly constructed.
It would be better to convert things like: ptime time(second_clock::universal_time()); In the next release you can convert from time_t if you insist like this: time_t now_t = time(0); ptime now = from_time_t(now_t);
When digging through the gregorian::date, i see that the constructors of date_time::date() from date_int_type and date_rep_type protected.
So, wouldn't it be better to make the gregorian::date() constructors from date_int_type and date_rep_type explicit, to get a compile-time error with this sample rather than the out-of-range-exception "Year is out of valid range: 1400..10000" ?
And another reason to make this constructor explicit might be that date_rep_type is the internal representation of date(), so when constructing date() with a day_count, you have to know the epoch, and then constructing date() should be done explicitly...
What do you think about this ?
I'll look into it. On first blush this would probably be reasonable. Jeff