Missing initializer warning in date_time/date_facet.hpp

[Derek McGowan <derek@…>]

include/boost/date_time/date_facet.hpp is causing a compiler warning

Compiler: gcc (GCC) 4.1.2 20080704 (Red Hat 4.1.2-48)

Compiler Options: g++4 -shared -fpic -g -Wall -Woverloaded-virtual -Werror -Wl,--warn-shared-textrel -Wl,--fatal-warnings

cc1plus: warnings being treated as errors
boost_1_46_1/include/boost/date_time/date_facet.hpp: In member function ‘OutItrT boost::date_time::date_facet<date_type, CharT, OutItrT>::put(OutItrT, std::ios_base&, CharT, const typename date_type::month_type&) const [with date_type = boost::gregorian::date, CharT = char, OutItrT = std::ostreambuf_iterator<char, std::char_traits<char> >]’:
boost_1_46_1/include/boost/date_time/gregorian/gregorian_io.hpp:243:   instantiated from ‘std::basic_ostream<_CharT, _Traits>& boost::gregorian::operator<<(std::basic_ostream<_CharT, _Traits>&, const boost::gregorian::greg_month&) [with CharT = char, TraitsT = std::char_traits<char>]’
<source>.cpp:##:   instantiated from here
boost_1_46_1/include/boost/date_time/date_facet.hpp:211: warning: missing initializer for member ‘tm::tm_sec’
boost_1_46_1/include/boost/date_time/date_facet.hpp:211: warning: missing initializer for member ‘tm::tm_min’
boost_1_46_1/include/boost/date_time/date_facet.hpp:211: warning: missing initializer for member ‘tm::tm_hour’
boost_1_46_1/include/boost/date_time/date_facet.hpp:211: warning: missing initializer for member ‘tm::tm_mday’
boost_1_46_1/include/boost/date_time/date_facet.hpp:211: warning: missing initializer for member ‘tm::tm_mon’
boost_1_46_1/include/boost/date_time/date_facet.hpp:211: warning: missing initializer for member ‘tm::tm_year’
boost_1_46_1/include/boost/date_time/date_facet.hpp:211: warning: missing initializer for member ‘tm::tm_wday’
boost_1_46_1/include/boost/date_time/date_facet.hpp:211: warning: missing initializer for member ‘tm::tm_yday’
boost_1_46_1/include/boost/date_time/date_facet.hpp:211: warning: missing initializer for member ‘tm::tm_isdst’
boost_1_46_1/include/boost/date_time/date_facet.hpp:211: warning: missing initializer for member ‘tm::tm_gmtoff’
boost_1_46_1/include/boost/date_time/date_facet.hpp:211: warning: missing initializer for member ‘tm::tm_zone’

std::tm dtm = {}; should be changed to something like std::tm dtm = std::tm();

This same issue was addressed and fixed in #3563

[Derek McGowan <derek@…>]

Setting component to date_time

[Manish Mulimani <manish.mulimani@…>]

Can I work on this bug?

[Manish Mulimani <manish.mulimani@…>]

Patch for the bug.

[Derek McGowan <derek@…>]

This is breaking our compilation, so I am upgrading it from cosmetic to a problem. Please submit patch.

[Marshall Clow]

(In [80710]) Use memset instead of default constructor (std::tm) for deficient compilers; Refs #5550

[Marshall Clow]

(In [80797]) Merge bug fixes to release; Fixes #5550 Fixes #6136 Fixes #6513 Fixes #7111 Fixes #7112 Fixes #7113 Fixes #7342 Fixes #7426

[Johan Lundberg <lundberj@…>]

This problem is there at two more places in another file (boost 1.54 beta1), giving the same errors/warnings as above.

/date_time/strings_from_facet.hpp:53:20: warning: missing initializer for member ‘tm::tm_gmtoff’ [-Wmissing-field-initializers] (and ten more like it)

/date_time/strings_from_facet.hpp:106:20: warning: missing initializer for member ‘tm::tm_zone’ [-Wmissing-field-initializers] (and ten more like it)

Now, changeset ​https://svn.boost.org/trac/boost/changeset/80797 suggest the change from

tm tm_value = {};

to

std::tm dtm; std::memset(&dtm, 0, sizeof(dtm));

I've made this change (at two places) and that silences all related warnings. Using the more obvious tm_value = {0,0,0,0,0,0,0,0,0} is not a good idea since some implementations add their own values at the end of the struct.

How to reproduce:

#include "date_time/posix_time/posix_time.hpp" int main(){}

compile with gcc4.7.2, default options.

[Marshall Clow]

(In [84835]) Fixed more compiler warnings; Refs #5550

[Marshall Clow]

(In [84860]) Merge bug fixes to release. Fixes #6136. Fixes #5550