C++ for Scientists - Technische Universität Dresden

4.7. NON-TYPE PARAMETERS FOR TEMPLATES 109
4.7 Non-Type Parameters for Templates
So far, we used template arguments only for types. Values can be template arguments as well.
Not all values but only integral types, i.e. fixed point numbers and bool.
Very popular is the definition of short vectors and small matrices with size arguments as template
parameters, for instance:
template
class fsize vector
{
typedef fsize vector self;
void check index(int i) const { assert(i >= 0 && i < my size); }
public:
typedef T value type;
const static int my size= Size;
fsize vector() {}
fsize vector( const self& that )
{
for (int i= 0; i < my size; ++i)
data[i]= that.data[i];
}
self& operator=( const self& that )
{
for (int i= 0; i < my size; ++i)
data[i]= that.data[i];
}
int size() const { return my size ; }
const T& operator[]( int i ) const
{
check index(i);
return data[i];
}
T& operator[]( int i )
{
check index(i);
return data[i] ;
}
self operator+( const self& that ) const
{
self sum;
for (int i= 0; i < my size; ++i)
sum[i]= data[i] + that[i];
return sum ;
}
private: