Declaration of Templates

[Sentinel]

How are templates declared in the header file?
E.g. I have the following function template in .cpp:


template<typename T>
bool Class::Check(const T &value)
{
return value != value;
}


What is the difference from the above template to the one
below? The difference is the "bool and the T", could you
please explain this?


template <typename T>
T max(T x, T y)
{
return (x > y) ? x : y;
}

Thanks for help.

[jlb]

The difference is the "bool and the T", could you
please explain this?

Well the first function belongs to a larger template class, called Class (A poor name for a class by the way.). The second is a template function that is not part of an actual class.

The first snippet, the member function, compares the value passed into the function with a value held in the class and returns whether the two values are equal or not, a bool value.

The second, non-class function, compares the two values passed into the function and returns the higher value. Note that both of the parameters and the return value have the same type 'T'.

[Sentinel]

And how are the templates declared in the header?

[kbw]

The templates aren't normally defined in the .cpp file, but in the header file.

So the example code you've provided should go in the header file.

[JLBorges]

Note that this compares the argument value with itself.

template<typename T>
bool Class::Check(const T &value)
{	
      return value != value;  // **** 
}

Perhaps, this is what was intended:

template<typename T>
bool Class::Check( const T &value ) const // EDIT: make it const-correct
{	
      return value != Class::value;  // **** 
}