Non-type parameters for templates

Besides the template arguments that are preceded by the class or typename keywords , which represent types, templates can also have regular typed parameters, similar to those found in functions. As an example, have a look at this class template that is used to contain sequences of elements

  std;
 < T,  N>
 mysequence {
T memblock [N];
:
 setmember ( x, T value);
T getmember ( x);
};
 < T,  N>
 mysequence<T,N>::setmember ( x, T value) {
memblock[x]=value;
}
 < T,  N>
T mysequence<T,N>::getmember ( x) {
 memblock[x];
}
 main () {
mysequence <,5> myints;
mysequence <,5> myfloats;
myints.setmember (0,100);
myfloats.setmember (3,3.1416);
cout << myints.getmember(0) << ;
cout << myfloats.getmember(3) << ;
 0;
}

It is also possible to set default values or types for class template parameters. For example, if the previous class template definition had been:

< T=, N=10> mysequence {..};

We could create objects using the default template parameters by declaring:

mysequence<> myseq;

Which would be equivalent to:

mysequence<,10> myseq;

 

转载于:https://www.cnblogs.com/cloudseawang/archive/2007/07/21/826694.html