16.3. Overloading and Templates
by Barbara E. Moo, Josée Lajoie, Stanley B. Lippman
C++ Primer, Fifth Edition
- Title Page
- Copyright Page
- Dedication Page
- Contents
- New Features in C++11
- Preface
- Chapter 1. Getting Started
- Part I. The Basics
- Contents
- Chapter 2. Variables and Basic Types
- Chapter 3. Strings, Vectors, and Arrays
- Chapter 4. Expressions
- Contents
- 4.1. Fundamentals
- 4.2. Arithmetic Operators
- 4.3. Logical and Relational Operators
- 4.4. Assignment Operators
- 4.5. Increment and Decrement Operators
- 4.6. The Member Access Operators
- 4.7. The Conditional Operator
- 4.8. The Bitwise Operators
- 4.9. The sizeof Operator
- 4.10. Comma Operator
- 4.11. Type Conversions
- 4.12. Operator Precedence Table
- Chapter Summary
- Defined Terms
- Chapter 5. Statements
- Chapter 6. Functions
- Chapter 7. Classes
- Part II. The C++ Library
- Contents
- Chapter 8. The IO Library
- Chapter 9. Sequential Containers
- Chapter 10. Generic Algorithms
- Chapter 11. Associative Containers
- Chapter 12. Dynamic Memory
- Part III. Tools for Class Authors
- Contents
- Chapter 13. Copy Control
- Chapter 14. Overloaded Operations and Conversions
- Contents
- 14.1. Basic Concepts
- 14.2. Input and Output Operators
- 14.3. Arithmetic and Relational Operators
- 14.4. Assignment Operators
- 14.5. Subscript Operator
- 14.6. Increment and Decrement Operators
- 14.7. Member Access Operators
- 14.8. Function-Call Operator
- 14.9. Overloading, Conversions, and Operators
- Chapter Summary
- Defined Terms
- Chapter 15. Object-Oriented Programming
- Contents
- 15.1. OOP: An Overview
- 15.2. Defining Base and Derived Classes
- 15.3. Virtual Functions
- 15.4. Abstract Base Classes
- 15.5. Access Control and Inheritance
- 15.6. Class Scope under Inheritance
- 15.7. Constructors and Copy Control
- 15.8. Containers and Inheritance
- 15.9. Text Queries Revisited
- Chapter Summary
- Defined Terms
- Chapter 16. Templates and Generic Programming
- Part IV. Advanced Topics
- Contents
- Chapter 17. Specialized Library Facilities
- Chapter 18. Tools for Large Programs
- Chapter 19. Specialized Tools and Techniques
- Appendix A. The Library
- Contents
- A.1. Library Names and Headers
- A.2. A Brief Tour of the Algorithms
- A.2.1. Algorithms to Find an Object
- A.2.2. Other Read-Only Algorithms
- A.2.3. Binary Search Algorithms
- A.2.4. Algorithms That Write Container Elements
- A.2.5. Partitioning and Sorting Algorithms
- A.2.6. General Reordering Operations
- A.2.7. Permutation Algorithms
- A.2.8. Set Algorithms for Sorted Sequences
- A.2.9. Minimum and Maximum Values
- A.2.10. Numeric Algorithms
- A.3. Random Numbers
- Index
- Add Pages
16.3. Overloading and Templates
Function templates can be overloaded by other templates or by ordinary, nontemplate functions. As usual, functions with the same name must differ either as to the number or the type(s) of their parameters.
Exercises Section 16.2.7
Exercise 16.47: Write your own version of the flip function and test it by calling functions that have lvalue and rvalue reference parameters.
Function matching (§ 6.4, p. 233) is affected by the presence of function templates in the following ways:
• The candidate functions for a call include any function-template instantiation for which template argument deduction (§ 16.2, p. 678) succeeds.
• The candidate function templates are always viable, because template argument deduction will have eliminated any templates that are not viable.
• As usual, the viable functions (template and nontemplate) are ranked by the conversions, if any, needed to make the call. Of course, the conversions used to call a function template are quite limited (§ 16.2.1, p. 679).
• Also as usual, if exactly one function provides a better match than any of the others, that function is selected. However, if there are several functions that provide an equally good match, then:
– If there is only one nontemplate function in the set of equally good matches, the nontemplate function is called.
– If there are no nontemplate functions in the set, but there are multiple function templates, and one of these templates is more specialized than any of the others, the more specialized function template is called.
– Otherwise, the call is ambiguous.
Warning-
No Comment