wangxiaohu wrote:
I am trying to write a class myVector based on std::vector and add
only a sort method.
BadIdea(tm). That is abuse of inheritance. You should use a free standing
function instead:
template < typename T, typename A >
void sort_vector ( std::vector<T,A> & sequence ) {
std::sort( sequence.begin(), sequence.end() );
}
or maybe even more generic:
template < typename Container >
void sort_sequence ( Container & sequence ) {
std::sort( sequence.begin(), sequence.end() );
}
or with a concept check:
template < typename Container >
void sort_sequence
( Container & sequence,
typename enable_if
< is_sequence< Container >::value, void* >::type = 0 ) {
std::sort( sequence.begin(), sequence.end() );
}
There are some cases where public inheritance from std::vector<> is
justified. This does not look like one of them.
The sort method needs to access the array stored
in the base class using iterator. I have following draft code. However
it never compile. Can anyone take a look and tell me how to fix it?
Thanks!
#include <vector>
#include <iostream>
using namespace std;
Don't put using directives in header files. Your decision to pull all
identifiers from the standard namespace is inflicted upon every user of
your class. That is very intrusive.
template <typename T> class myVector : public vector<T>
{
public:
void Sort();
};
template <typename T> void Sort<T>::Sort()
Shouldn't that be something like
template <typename T>
void myVector::Sort()
{
if (this.size() < 2)
{
return;
}
vector<T>::iterator i;
You would need to say
typename std::vector<T>::iterator i;
The keyword here is "dependent name".
for (i = this.begin(); i != this.end(); i++)
{
//rest part ignored....
}
}
BTW: why are you doing your own sort algorithm? any why only for vectors? It
is _very_ hard to beat std::sort() from the header <algorithm>.
Best
Kai-Uwe Bux