Re: hasMember
Jeff Flinn <TriumphSprint2000@hotmail.com> writes:
To avoid the memory allocation and ownership issues use boost::optional.
#include <boost/optional.hpp>
typedef boost::optional<int> optional_int;
optional_int Cont::getValue(int idx) const
{
std::map<int, int>::const_iterator itr = content.find(idx);
return (itr != cont.end())? itr->second : optional_int();
}
and:
if(optional_int i = obj.getValue(idx)) // safe bool idiom
{
int x = *i + 123; // deref for value
}
Using exceptions in this case could be good?
Seems out of place for the use you've described, given what little
info you've provided.
Jeff
Interesting the optional_int, but I can't use boost...
Anyway I didn't specify much because is a general (for me) problem,
every time I have a class which has some structure (set/vector/map) I
might want to check and get some values from it.
So returning -1 or NULL is for me not nice, using exceptions I meant
something like done in std::vector::at for example
try {
int x = vec.at(0);
} catch ...
I could throw an exception whenever I don't find the value and catch it
in the caller, that's what I meant..