1.3.2 Template function

• When you use template function with real argument, compiler will extract type information form real argument, then generate real function code for you. So it will make compiler looks longer.
  swap(i1, i2); 
  swap(f1, f2); 
  // don’t need to specify int, compiler 
  //can extract type information from i1 
   
  // compiler will produce two swap functions bodies.
• Why we need a overload template function, Because not all type support the same operator. For example, in your template function, you use = operator, but when you use array for this template function type, compiler will report error.
  template <typename T> 
  void swap(T a[], T b[], int n) 
   
  template <typename T> 
  void swap(T &a, T &b )
• Overload is different with Specializations, Overload means that you have different function signatures. Specialization have the same function signature.
• "Why Not Specialize Function Templates?" You can see it in the ref.
• "Why Argument Dependent Lookup doesn’t work with function template dynamic_pointer_cast". See it in the ref
• "C++ template function taking template class as parameter" See in ref.