Re: [Boost-users] Boost Date/Time

Subject: Re: [Boost-users] Boost Date/Time
From: Michael Chisholm (chisholm_at_[hidden])
Date: 2012-02-13 18:09:10

The comment in your code indicates that the custom_locale object "owns" 
the facet you pass it.  Therefore when the locale object goes out of 
scope, it will delete the facet.  But if the facet was allocated on the 
stack, you aren't allowed to delete it.  So that is an error. 
Stack-allocated objects are automatically destroyed when the stack frame 
is destroyed (and similarly with nested scopes...).  You don't get to 
delete them explicitly.  So don't pass their addresses into objects who 
will do that.

Andy

On 2/13/2012 6:01 AM, asif saeed wrote:
> Hi,
>
> I get a run-time error when I run the following code;
>
> std::string LocaleFormattedDateTime (::boost::posix_time::ptime pt)
> {
>    std::string s;
>    std::ostringstream ss;
>
>    //::boost::posix_time::time_facet * tf = new
> ::boost::posix_time::time_facet;
>    ::boost::posix_time::time_facet tf;
>    //std::locale custom_locale (std::locale(""), tf);
>    std::locale custom_locale (std::locale(""),&tf);
>
>    // custom_locale takes ownership of the tf facet
>    ss.imbue (custom_locale);
>    //(*tf).format("%Y%m%d-%H%M%S-%f"); // date time
>    tf.format("%Y%m%d-%H%M%S-%f"); // date time
>    ss<<  pt;
>    // don't explicitly delete tf - what's wrong with a stack variable? why
> this runtime error? What is the point of new() above and
>                                       //what if I don't delete allocated
> memory here.
>    return ss.str();
> }
>
> void CurrentDateTimeWithMicroseconds(char s[], int sz = 100)
> {
> using namespace boost::posix_time;
> using namespace std;
> using boost::date_time::date_facet;
>
> ptime t = microsec_clock::local_time();
> ostringstream ss;
> //time_facet *df = new time_facet();
> time_facet df;
> //std::locale loc (std::locale(""), df);
> std::locale loc (std::locale(""),&df);
> ss<<  LocaleFormattedDateTime(t) ;
> memset(s,0,sz);
> strcpy(s,ss.str().c_str());
> }
>
> Can you tell me the problem?
>
> I modified this code after copying this from some online source.
>
> Thanks in advance, Asif
>
>
>
>
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