Boost C++ Libraries: Ticket #5227: find_ptr wrapper for map::find

Marshall Clow — Thu, 15 Mar 2012 18:30:10 GMT

How about declaring the variable in the if statement?

if (auto i = very_long_name.find(1) != very_long_name.end())
     cout << i->second;
}

That makes the code simpler. I'm not dismissing the suggestion for a wrapper; just looking at alternatives as well.

Thu, 15 Mar 2012 18:33:51 GMT

Yeah, except that I is now a bool. ;)

Marshall Clow — Thu, 15 Mar 2012 18:41:32 GMT

Dang. Apparently the compiler in my head is defective. I need an upgrade.

viboes — Sun, 03 Jun 2012 20:22:54 GMT

Are you sure it is safe to return &i->second? What about returning optional<typename T::mapped_type>?

Sun, 03 Jun 2012 21:25:53 GMT

Yes, I am.

Mon, 02 Jul 2012 17:24:10 GMT

To avoid issues with ptr_container, T::value_type::second_type should be used instead of T::mapped_type

template <class T, class U>
typename T::value_type::second_type* find_ptr(T& c, U v)
{
	typename T::iterator i = c.find(v);
	return i == c.end() ? NULL : &i->second;
}
template <class T, class U>
const typename T::value_type::second_type* find_ptr(const T& c, U v)
{
	typename T::const_iterator i = c.find(v);
	return i == c.end() ? NULL : &i->second;
}

Marshall Clow — Mon, 09 Jul 2012 17:31:21 GMT

(In [79385]) Find wrappers for map/multimap; suggested by Olaf; Refs #5227; No docs yet.

owner, component changed

Marshall Clow — Mon, 09 Jul 2012 17:32:03 GMT

owner changed from No-Maintainer to Marshall Clow
component utility → algorithm

milestone changed

Marshall Clow — Mon, 09 Jul 2012 17:32:24 GMT

milestone Boost 1.47.0 → Boost 1.52.0

Wed, 10 Oct 2012 09:32:28 GMT

Did this make it into 1.52? Can't find it.

Wed, 09 Jan 2013 14:28:56 GMT

Marshall?