What are the Advantages/Drawbacks of these two ways of iterating through a container / which one do you prefer and why:
for (MyClass::iterator i = m.begin(), e = m.end() ; i != e ; i++)
{
// ...
}
or
for (MyClass::iterator i = m.begin() ; i != m.end() ; i++)
{
// ...
}
Subsidiary question: i++ or ++i? Why?
If the iterator is non-trivial (ie. not a pointer), ++i is definitely faster as it doesn't involves a copy to a temporary, which may or may not be optimized out.
The first form is a little faster but could be wrong if you erase or insert things in the loop.
For simple iteration over a container I use
#define foreach BOOST_FOREACH // in some header
foreach(MyType &element, any_container) {
// deal with element
}
most of the time for succinctness and clarity.