C++ Annotations Version 12.2.0

Frank B. Brokken

University of Groningen,
PO Box 407,
9700 AK Groningen
The Netherlands
ISBN 90 367 0470 7

1994-2022

This document is intended for knowledgeable users of C (or any other language using a C-like grammar, like Perl or Java) who would like to know more about, or make the transition to, C++. This document is the main textbook for Frank's C++ programming courses, which are yearly organized at the University of Groningen. The C++ Annotations do not cover all aspects of C++, though. In particular, C++'s basic grammar is not covered when equal to C's grammar. Any basic book on C may be consulted to refresh that part of C++'s grammar.

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Table of Contents

Chapter 1: Overview Of The Chapters

Chapter 2: Introduction

2.1: What's new in the C++ Annotations

2.2: C++'s history

2.2.1: History of the C++ Annotations

2.2.2: Compiling a C program using a C++ compiler

2.2.3: Compiling a C++ program

2.2.3.1: C++ under MS-Windows

2.2.3.2: Compiling a C++ source text

2.3: C++: advantages and claims

2.4: What is Object-Oriented Programming?

2.5: Differences between C and C++

2.5.1: The function `main'

2.5.2: End-of-line comment

2.5.3: Strict type checking

2.5.4: Function Overloading

2.5.5: Default function arguments

2.5.6: NULL-pointers vs. 0-pointers and nullptr

2.5.7: The `void' parameter list

2.5.8: The `#define __cplusplus'

2.5.9: Using standard C functions

2.5.10: Header files for both C and C++

2.5.11: Defining local variables

2.5.12: The keyword `typedef'

2.5.13: Functions as part of a struct

2.5.14: Evaluation order of operands

Chapter 3: A First Impression Of C++

3.1: Notable differences with C

3.1.1: Using the keyword `const'

3.1.2: Namespaces

3.1.3: The scope resolution operator ::

3.1.4: `cout', `cin', and `cerr'

3.2: Functions as part of structs

3.2.1: Data hiding: public, private and class

3.2.2: Structs in C vs. structs in C++

3.3: Several additions to C's grammar

3.3.1: References

3.3.2: Rvalue References

3.3.3: Lvalues, rvalues and more

3.3.4: Strongly typed enumerations

3.3.5: Initializer lists

3.3.5.1: Designated initialization

3.3.6: Initializers for bit-fields

3.3.7: Type inference using `auto'

3.3.7.1: Structured binding declarations

3.3.8: Defining types and `using' declarations

3.3.9: Range-based for-loops

3.3.10: Raw String Literals

3.3.11: Binary constants

3.3.12: Selection statements with initializers

3.3.13: Attributes

3.3.14: Three-way comparison (<=>)

3.4: New language-defined data types

3.4.1: The data type `bool'

3.4.2: The data type `wchar_t'

3.4.3: Unicode encoding

3.4.4: The data type `long long int'

3.4.5: The data type `size_t'

3.4.6: std::byte

3.4.7: Digit separators

3.5: A new syntax for casts

3.5.1: The `static_cast'-operator

3.5.2: The `const_cast'-operator

3.5.3: The `reinterpret_cast'-operator

3.5.4: The `dynamic_cast'-operator

3.5.5: Casting 'shared_ptr' objects

3.6: Keywords and reserved names in C++

Chapter 4: Namespaces

4.1: Namespaces

4.1.1: Defining namespaces

4.1.1.1: Declaring entities in namespaces

4.1.1.2: A closed namespace

4.1.2: Referring to entities

4.1.2.1: The `using' directive

4.1.2.2: `Koenig lookup'

4.1.3: The standard namespace

4.1.4: Nesting namespaces and namespace aliasing

4.1.4.1: Defining entities outside of their namespaces

4.2: The std::chrono namespace (handling time)

4.2.1: Time resolutions: std::ratio

4.2.2: Amounts of time: std::chrono::duration

4.2.3: Clocks measuring time

4.2.4: Points in time: std::chrono::time_point

4.3: The std::filesystem namespace

4.3.1: the '__file_clock' type

4.3.2: The class 'error_code'

4.3.3: Names of file system entries: path

4.3.3.1: Accessors, modifiers and operators

4.3.3.2: Free functions

4.3.4: Handling directories: directory_entry

4.3.4.1: Visiting directory entries: (recursive_)directory_iterator

4.3.5: Types (file_type) and permissions (perms) of file system elements: file_status

4.3.5.1: Obtaining the status of file system entries

4.3.6: Information about the space of file systems: space_info

4.3.7: File system exceptions: filesystem_error

Chapter 5: The `string' Data Type

5.1: Operations on strings

5.2: A std::string reference

5.2.1: Initializers

5.2.2: Iterators

5.2.3: Operators

5.2.4: Member functions

5.2.5: Conversion functions

5.3: std::string_view

Chapter 6: The IO-stream Library

6.1: Special header files

6.2: The foundation: the class `ios_base'

6.3: Interfacing `streambuf' objects: the class `ios'

6.3.1: Condition states

6.3.2: Formatting output and input

6.3.2.1: Format modifying member functions

6.3.2.2: Formatting flags

6.4: Output

6.4.1: Basic output: the class `ostream'

6.4.1.1: Writing to `ostream' objects

6.4.1.2: `ostream' positioning

6.4.1.3: `ostream' flushing

6.4.2: Output to files: the class `ofstream'

6.4.2.1: Modes for opening stream objects

6.4.3: Output to memory: the class `ostringstream'

6.4.4: The `put_time' manipulator

6.5: Input

6.5.1: Basic input: the class `istream'

6.5.1.1: Reading from `istream' objects

6.5.1.2: `istream' positioning

6.5.2: Input from files: the class `ifstream'

6.5.3: Input from memory: the class `istringstream'

6.5.4: Copying streams

6.5.5: Coupling streams

6.6: Advanced topics

6.6.1: Moving streams

6.6.2: Redirecting streams

6.6.3: Reading AND Writing streams

Chapter 7: Classes

7.1: The constructor

7.1.1: A first application

7.1.2: Constructors: with and without arguments

7.1.2.1: The order of construction

7.2: Ambiguity resolution

7.2.1: Types `Data' vs. `Data()'

7.2.2: Superfluous parentheses

7.2.3: Existing types

7.3: Objects inside objects: composition

7.3.1: Composition and (const) objects: (const) member initializers

7.3.2: Composition and reference objects: reference member initializers

7.4: Data member initializers

7.4.1: Delegating constructors

7.5: Uniform initialization

7.6: Defaulted and deleted class members

7.7: Const member functions and const objects

7.7.1: Anonymous objects

7.7.1.1: Subtleties with anonymous objects

7.8: The keyword `inline'

7.8.1: Defining members inline

7.8.2: When to use inline functions

7.8.2.1: A prelude: when NOT to use inline functions

7.8.3: Inline variables

7.9: Local classes: classes inside functions

7.10: The keyword `mutable'

7.11: Header file organization

7.11.1: Using namespaces in header files

7.11.2: Modules

7.12: Sizeof applied to class data members

Chapter 8: Static Data And Functions

8.1: Static data

8.1.1: Private static data

8.1.2: Public static data

8.1.3: Initializing static const data

8.1.4: Generalized constant expressions (constexpr)

8.1.4.1: Constant expression data

8.2: Static member functions

8.2.1: Calling conventions

Chapter 9: Classes And Memory Allocation

9.1: Operators `new' and `delete'

9.1.1: Allocating arrays

9.1.2: Deleting arrays

9.1.3: Enlarging arrays

9.1.4: Managing `raw' memory

9.1.5: The `placement new' operator

9.2: The destructor

9.2.1: Object pointers revisited

9.2.2: The function set_new_handler()

9.3: The assignment operator

9.3.1: Overloading the assignment operator

9.3.1.1: The member 'operator=()'

9.4: The `this' pointer

9.4.1: Sequential assignments and this

9.5: The copy constructor: initialization vs. assignment

9.6: Revising the assignment operator

9.6.1: Swapping

9.6.1.1: Fast swapping

9.7: Moving data

9.7.1: The move constructor (dynamic data)

9.7.2: The move constructor (composition)

9.7.3: Move-assignment

9.7.4: Revising the assignment operator (part II)

9.7.5: Moving and the destructor

9.7.6: Move-only classes

9.7.7: Default move constructors and assignment operators

9.7.8: Moving: implications for class design

9.8: Copy Elision and Return Value Optimization

9.9: Unrestricted Unions

9.9.1: Implementing the destructor

9.9.2: Embedding an unrestricted union in a surrounding class

9.9.3: Swapping unrestricted unions

9.9.4: Assignment

9.10: Aggregate Data Types

9.11: Conclusion

Chapter 10: Exceptions

10.1: Exception syntax

10.2: An example using exceptions

10.2.1: Anachronisms: `setjmp' and `longjmp'

10.2.2: Exceptions: the preferred alternative

10.3: Throwing exceptions

10.3.1: The empty `throw' statement

10.4: The try block

10.5: Catching exceptions

10.5.1: The default catcher

10.6: Functions that cannot throw exceptions: the `noexcept' keyword

10.7: Iostreams and exceptions

10.8: Standard exceptions

10.8.1: Standard exceptions: to use or not to use?

10.9: System error, error_category, and error_condition

10.9.1: The class `std::error_category'

10.9.2: The class `std::error_condition'

10.9.3: The class system_error

10.10: Exception guarantees

10.10.1: The basic guarantee

10.10.2: The strong guarantee

10.10.3: The nothrow guarantee

10.11: Function try blocks

10.12: Exceptions in constructors and destructors

Chapter 11: More Operator Overloading

11.1: Overloading `operator[]()'

11.2: Overloading insertion and extraction operators

11.3: Conversion operators

11.4: The keyword `explicit'

11.4.1: Explicit conversion operators

11.5: Overloading increment and decrement operators

11.6: Overloading binary operators

11.6.1: Member function reference bindings (& and &&)

11.6.2: The three-way comparison operator `<=>'

11.7: Overloading `operator new(size_t)'

11.8: Overloading `operator delete(void *)'

11.9: Operators `new[]' and `delete[]'

11.9.1: Overloading `new[]'

11.9.2: Overloading `delete[]'

11.9.3: The `operator delete(void *, size_t)' family

11.9.4: `new[]', `delete[]' and exceptions

11.10: Function Objects

11.10.1: Constructing manipulators

11.10.1.1: Manipulators requiring arguments

11.11: Lambda expressions

11.11.1: Lambda expressions: syntax

11.11.2: Using lambda expressions

11.12: The case of [io]fstream::open()

11.13: User-defined literals

11.14: Overloadable operators

Chapter 12: Abstract Containers

12.1: Notations used in this chapter

12.2: The `pair' container

12.3: Allocators

12.4: Available Containers

12.4.1: The `array' container

12.4.2: The `vector' container

12.4.3: The `list' container

12.4.4: The `queue' container

12.4.5: The `priority_queue' container

12.4.6: The `deque' container

12.4.7: The `map' container

12.4.7.1: The `map' constructors

12.4.7.2: The `map' operators

12.4.7.3: The `map' public members

12.4.7.4: The `map': a simple example

12.4.8: The `multimap' container

12.4.9: The `set' container

12.4.10: The `multiset' container

12.4.11: The `stack' container

12.4.12: The `unordered_map' container (`hash table')

12.4.12.1: The `unordered_map' constructors

12.4.12.2: The `unordered_map' public members

12.4.12.3: The `unordered_multimap' container

12.4.13: The `unordered_set' container

12.4.13.1: The `unordered_multiset' container

12.4.14: Heterogeneous lookup

12.5: The `complex' container

Chapter 13: Inheritance

13.1: Related types

13.1.1: Inheritance depth: desirable?

13.2: Access rights: public, private, protected

13.2.1: Public, protected and private derivation

13.2.2: Promoting access rights

13.3: The constructor of a derived class

13.3.1: Move construction

13.3.2: Move assignment

13.3.3: Inheriting constructors

13.3.4: Aggregate Initializations

13.4: The destructor of a derived class

13.5: Redefining member functions

13.6: Multiple inheritance

13.7: Conversions between base classes and derived classes

13.7.1: Conversions with object assignments

13.7.2: Conversions with pointer assignments

13.8: Using non-default constructors with new[]

Chapter 14: Polymorphism

14.1: Virtual functions

14.2: Virtual destructors

14.3: Pure virtual functions

14.3.1: Implementing pure virtual functions

14.4: Explicit virtual overrides

14.5: Virtual functions and multiple inheritance

14.5.1: Ambiguity in multiple inheritance

14.5.2: Virtual base classes

14.5.3: When virtual derivation is not appropriate

14.6: Run-time type identification

14.6.1: The dynamic_cast operator

14.6.2: The `typeid' operator

14.7: Inheritance: when to use to achieve what?

14.8: The `streambuf' class

14.8.1: Protected `streambuf' members

14.8.1.1: Protected members for input operations

14.8.1.2: Protected members for output operations

14.8.1.3: Protected members for buffer manipulation

14.8.1.4: Deriving classes from `streambuf'

14.8.2: The class `filebuf'

14.8.3: Safely interfacing streams to another std::streambuf

14.9: A polymorphic exception class

14.10: How polymorphism is implemented

14.11: Undefined reference to vtable ...

14.12: Virtual constructors

Chapter 15: Friends

15.1: Friend functions

15.2: Extended friend declarations

Chapter 16: Classes Having Pointers To Members

16.1: Pointers to members: an example

16.2: Defining pointers to members

16.3: Using pointers to members

16.4: Pointers to static members

16.5: Pointer sizes

Chapter 17: Nested Classes

17.1: Defining nested class members

17.2: Declaring nested classes

17.3: Accessing private members in nested classes

17.4: Nesting enumerations

17.4.1: Empty enumerations

17.5: Revisiting virtual constructors

Chapter 18: The Standard Template Library

18.1: Predefined function objects

18.1.1: Arithmetic function objects

18.1.2: Relational function objects

18.1.3: Logical function objects

18.1.4: The `std::not_fn' negator

18.2: Iterators

18.2.1: std::distance and std::size

18.2.2: Insert iterators

18.2.3: Iterators for `istream' objects

18.2.3.1: Iterators for `istreambuf' objects

18.2.4: Iterators for `ostream' objects

18.2.4.1: Iterators for `ostreambuf' objects

18.3: The class 'unique_ptr'

18.3.1: Defining `unique_ptr' objects

18.3.2: Creating a plain `unique_ptr'

18.3.3: Moving another `unique_ptr'

18.3.4: Pointing to a newly allocated object

18.3.5: Operators and members

18.3.6: Using `unique_ptr' objects for arrays

18.4: The class `shared_ptr'

18.4.1: Defining `shared_ptr' objects

18.4.2: Creating a plain `shared_ptr'

18.4.3: Pointing to a newly allocated object

18.4.4: Operators and members

18.4.5: Casting shared pointers

18.4.6: Using `shared_ptr' objects for arrays

18.5: Smart `smart pointer' construction: `make_shared' and `make_unique'

18.6: Classes having pointer data members

18.7: Comparison classes

18.7.1: The class `weak_equality'

18.7.2: The class `strong_equality'

18.7.3: The class `partial_ordering'

18.7.4: The class `weak_ordering'

18.7.5: The class `strong_ordering'

18.8: Regular Expressions

18.8.1: The regular expression mini language

18.8.1.1: Character classes

18.8.2: Defining regular expressions: std::regex

18.8.3: Retrieving matches: std::match_results

18.8.4: Regular expression matching functions

18.8.4.1: The std::regex_constants::match_flag_type flags

18.8.4.2: Matching full texts: std::regex_match

18.8.4.3: Partially matching text: std::regex_search

18.8.4.4: The member std::match_results::format

18.8.4.5: Modifying target strings: std::regex_replace

18.9: Randomization and Statistical Distributions

18.9.1: Random Number Generators

18.9.2: Statistical distributions

18.9.2.1: Bernoulli distribution

18.9.2.2: Binomial distribution

18.9.2.3: Cauchy distribution

18.9.2.4: Chi-squared distribution

18.9.2.5: Extreme value distribution

18.9.2.6: Exponential distribution

18.9.2.7: Fisher F distribution

18.9.2.8: Gamma distribution

18.9.2.9: Geometric distribution

18.9.2.10: Log-normal distribution

18.9.2.11: Normal distribution

18.9.2.12: Negative binomial distribution

18.9.2.13: Poisson distribution

18.9.2.14: Student t distribution

18.9.2.15: Uniform int distribution

18.9.2.16: Uniform real distribution

18.9.2.17: Weibull distribution

18.10: tie

18.11: Optional return values

Chapter 19: The STL Generic Algorithms

19.1: The Generic Algorithms

19.1.1: accumulate

19.1.2: adjacent_difference

19.1.3: adjacent_find

19.1.4: binary_search

19.1.5: copy

19.1.6: copy_backward

19.1.7: count

19.1.8: count_if

19.1.9: equal

19.1.10: equal_range

19.1.11: exchange

19.1.12: fill

19.1.13: fill_n

19.1.14: find

19.1.15: find_end

19.1.16: find_first_of

19.1.17: find_if

19.1.18: for_each

19.1.19: generate

19.1.20: generate_n

19.1.21: includes

19.1.22: inner_product

19.1.23: inplace_merge

19.1.24: iota

19.1.25: iter_swap

19.1.26: lexicographical_compare

19.1.27: lower_bound

19.1.28: max

19.1.29: max_element

19.1.30: merge

19.1.31: min

19.1.32: min_element

19.1.33: mismatch

19.1.34: next_permutation

19.1.35: nth_element

19.1.36: partial_sort

19.1.37: partial_sort_copy

19.1.38: partial_sum

19.1.39: partition

19.1.40: prev_permutation

19.1.41: remove

19.1.42: remove_copy

19.1.43: remove_copy_if

19.1.44: remove_if

19.1.45: replace

19.1.46: replace_copy

19.1.47: replace_copy_if

19.1.48: replace_if

19.1.49: reverse

19.1.50: reverse_copy

19.1.51: rotate

19.1.52: rotate_copy

19.1.53: search

19.1.54: search_n

19.1.55: set_difference

19.1.56: set_intersection

19.1.57: set_symmetric_difference

19.1.58: set_union

19.1.59: sort

19.1.60: stable_partition

19.1.61: stable_sort

19.1.62: swap

19.1.63: swap_ranges

19.1.64: transform

19.1.65: unique

19.1.66: unique_copy

19.1.67: upper_bound

19.1.68: Heap algorithms

19.1.68.1: The `make_heap' function

19.1.68.2: The `pop_heap' function

19.1.68.3: The `push_heap' function

19.1.68.4: The `sort_heap' function

19.1.68.5: An example using the heap functions

Chapter 20: Multi Threading

20.1: Multi Threading

20.1.1: The namespace std::this_thread

20.1.2: The class std::thread

20.1.2.1: Static data and threads: thread_local

20.1.2.2: Exceptions and join()

20.1.3: The class std::jthread

20.1.3.1: std::stop_callback

20.2: Synchronization (mutexes)

20.2.1: Initialization in multi-threaded programs

20.2.2: Shared mutexes

20.3: Locks and lock handling

20.3.1: Deadlocks

20.3.2: Shared locks

20.4: Event handling (condition variables)

20.4.1: The class std::condition_variable

20.4.2: The class std::condition_variable_any

20.4.3: An example using condition variables

20.5: Atomic actions: mutexes not required

20.6: An example: threaded quicksort

20.7: Shared States

20.8: Asynchronous return objects: std::future

20.8.1: The std::future_error exception and the std::future_errc enum

20.9: Shared asynchronous return objects: std::shared_future

20.10: Starting a new thread: std::async

20.11: Preparing a task for execution: std::packaged_task

20.12: The class `std::promise'

20.12.1: Exception propagation: std::exception_ptr

20.13: An example: multi-threaded compilations

20.14: Transactional Memory

20.15: Synchronizing output to streams

20.15.1: The `std::syncbuf' streambuf

20.15.2: Multi-threaded compilations using `osyncstream'

Chapter 21: Function and Variable Templates

21.1: Defining function templates

21.1.1: Considerations regarding template parameters

21.1.2: Auto and decltype

21.1.2.1: declval

21.1.3: Late-specified return type

21.2: Passing arguments by reference (reference wrappers)

21.3: Using local and unnamed types as template arguments

21.4: Template parameter deduction

21.4.1: Lvalue transformations

21.4.2: Qualification transformations

21.4.3: Transformation to a base class

21.4.4: The template parameter deduction algorithm

21.4.5: Template type contractions

21.5: Declaring function templates

21.5.1: Instantiation declarations

21.6: Instantiating function templates

21.6.1: Instantiations: no `code bloat'

21.7: Using explicit template types

21.8: Overloading function templates

21.8.1: An example using overloaded function templates

21.8.2: Ambiguities when overloading function templates

21.8.3: Declaring overloaded function templates

21.9: Specializing templates for deviating types

21.9.1: Avoiding too many specializations

21.9.2: Declaring specializations

21.9.3: Complications when using the insertion operator

21.10: Static assertions

21.11: Numeric limits

21.12: Polymorphous wrappers for function objects

21.13: Compiling template definitions and instantiations

21.14: The function selection mechanism

21.14.1: Determining the template type parameters

21.15: SFINAE: Substitution Failure Is Not An Error

21.16: Conditional function definitions using `if constexpr'

21.17: Summary of the template declaration syntax

21.18: Variables as templates (template variables)

Chapter 22: Class Templates

22.0.1: Template Argument Deduction

22.0.1.1: Simple Definitions

22.0.1.2: Explicit Conversions

22.1: Defining class templates

22.1.1: Constructing the circular queue: CirQue

22.1.2: Non-type parameters

22.1.3: Member templates

22.1.4: CirQue's constructors and member functions

22.1.5: Using CirQue objects

22.1.6: Default class template parameters

22.1.7: Declaring class templates

22.1.8: Preventing template instantiations

22.1.9: Generic lambda expressions

22.2: Static data members

22.2.1: Extended use of the keyword `typename'

22.3: Specializing class templates for deviating types

22.3.1: Example of a class specialization

22.4: Partial specializations

22.4.1: Intermezzo: some simple matrix algebraic concepts

22.4.2: The Matrix class template

22.4.3: The MatrixRow partial specialization

22.4.4: The MatrixColumn partial specialization

22.4.5: The 1x1 matrix: avoid ambiguity

22.5: Variadic templates

22.5.1: Defining and using variadic templates

22.5.2: Perfect forwarding

22.5.3: The unpack operator

22.5.4: Non-type variadic templates

22.5.5: Folding expressions

22.6: Tuples

22.6.1: Tuples and structured bindings

22.7: Computing the return type of function objects

22.8: Instantiating class templates

22.9: Processing class templates and instantiations

22.10: Declaring friends

22.10.1: Non-templates used as friends in templates

22.10.2: Templates instantiated for specific types as friends

22.10.2.1: Free operators as friends of nested classes

22.10.3: Unbound templates as friends

22.10.4: Extended friend declarations

22.11: Class template derivation

22.11.1: Deriving ordinary classes from class templates

22.11.2: Deriving class templates from class templates

22.11.3: Deriving class templates from ordinary classes

22.12: Static Polymorphism

22.12.1: An example of static polymorphism

22.12.2: Converting dynamic polymorphic classes to static polymorphic classes

22.12.3: Using static polymorphism to avoid reimplementations

22.13: Class templates and nesting

22.14: Constructing iterators

22.14.1: Implementing a `RandomAccessIterator'

22.14.2: Implementing a `reverse_iterator'

Chapter 23: Advanced Template Use

23.1: Subtleties

23.1.1: Returning types nested under class templates

23.1.2: Type resolution for base class members

23.1.3: ::template, .template and ->template

23.2: Template Meta Programming

23.2.1: Values according to templates

23.2.1.1: Converting integral types to types

23.2.2: Selecting alternatives using templates

23.2.2.1: Defining overloading members

23.2.2.2: Class structure as a function of template parameters

23.2.2.3: An illustrative example

23.2.3: Templates: Iterations by Recursion

23.3: User-defined literals

23.4: Template template parameters

23.4.1: Policy classes - I

23.4.2: Policy classes - II: template template parameters

23.4.2.1: The destructor of Policy classes

23.4.3: Structure by Policy

23.5: Alias Templates

23.6: Trait classes

23.6.1: Distinguishing class from non-class types

23.6.2: Available type traits

23.7: Defining `ErrorCodeEnum' and 'ErrorConditionEnum' enumerations

23.7.1: Deriving classes from std::error_category

23.8: Using `noexcept' when offering the `strong guarantee'

23.9: More conversions to class types

23.9.1: Types to types

23.9.2: An empty type

23.9.3: Type convertibility

23.9.3.1: Determining inheritance

23.10: Template TypeList processing

23.10.1: The length of a TypeList

23.10.2: Searching a TypeList

23.10.3: Selecting from a TypeList

23.10.4: Prefixing/Appending to a TypeList

23.10.5: Erasing from a TypeList

23.10.5.1: Erasing the first occurrence

23.10.5.2: Erasing a type by its index

23.10.5.3: Erasing all occurrences of a type

23.10.5.4: Erasing duplicates

23.11: Using a TypeList

23.11.1: The Wrap and Multi class templates

23.11.2: The MultiBase class template

23.11.3: Support templates

23.11.4: Using Multi

23.12: Expression Templates

23.12.1: Designing an Expression Template

23.12.2: Implementing an Expression Template

23.12.3: The BasicType trait class and ordering classes

23.13: Concepts

23.13.1: Defining concepts

23.13.2: Requirements

23.13.2.1: Simple requirements

23.13.2.2: Type requirements

23.13.2.3: Compound requirements

23.13.2.4: Nested requirements

23.13.3: Predefined concepts

23.13.3.1: Concepts specifying one template type parameter

23.13.3.2: Concepts specifying two template type parameters

23.13.3.3: Concepts specifying multiple template type parameters

23.13.4: Applying concepts to template parameter packs

23.13.5: Applying concepts to free functions

23.13.6: Implementing constrained class members

23.13.7: Constrained partial specializations

23.13.7.1: Function- and class template declarations

23.13.7.2: Bound free-operators

Chapter 24: Coroutines

24.1: Defining a coroutine

24.1.1: The coroutine's State class (promise_type)

24.1.1.1: What if `suspend_never' is used?

24.1.2: Simplifying the state class

24.2: Embedding coroutines in classes

24.2.1: The `Reader' coroutine handler

24.2.2: The `Writer' coroutine handler

24.3: `Awaitables', `Awaiters' and `co_await'

24.4: The class `Awaiter'

24.5: Accessing State from inside coroutines

24.6: Finite State Automatons via coroutines

24.6.1: The `Start' handler class

24.6.2: Completing the Finite State Automaton

24.7: Recursive coroutines

24.7.1: Recursively calling recursiveCoro

24.7.2: Beyond a single recursive call

24.8: Coroutine iterators

24.9: Visiting directories using coroutines

24.9.1: The `Dir' class showing directory entries

24.9.2: Visiting directories using coroutines

24.9.3: Functions vs. coroutines

Chapter 25: Concrete Examples

25.1: Using file descriptors with `streambuf' classes

25.1.1: Classes for output operations

25.1.2: Classes for input operations

25.1.2.1: Using a one-character buffer

25.1.2.2: Using an n-character buffer

25.1.2.3: Seeking positions in `streambuf' objects

25.1.2.4: Multiple `unget' calls in `streambuf' objects

25.1.3: Fixed-sized field extraction from istream objects

25.1.3.1: Member functions and example

25.2: The `fork' system call

25.2.1: A basic Fork class

25.2.2: Parents and Children

25.2.3: Redirection revisited

25.2.4: The `Daemon' program

25.2.5: The class `Pipe'

25.2.6: The class `ParentSlurp'

25.2.7: Communicating with multiple children

25.2.7.1: The class `Selector': interface

25.2.7.2: The class `Selector': implementation

25.2.7.3: The class `Monitor': interface

25.2.7.4: The class `Monitor': s_handler

25.2.7.5: The class `Monitor': the member `run'

25.2.7.6: The class `Monitor': example

25.2.7.7: The class `Child'

25.3: Adding binary operators to classes

25.3.1: Merely using operators

25.3.1.1: To namespace or not to namespace?

25.3.2: The CRTP and defining operator function templates

25.3.3: Insertion and extraction

25.4: Distinguishing lvalues from rvalues with operator[]()

25.5: Implementing a `reverse_iterator'

25.6: Using `bisonc++' and `flexc++'

25.6.1: Using `flexc++' to create a scanner

25.6.1.1: The derived class `Scanner'

25.6.1.2: The lexical scanner specification file

25.6.1.3: Implementing `Scanner'

25.6.1.4: Using a `Scanner' object

25.6.1.5: Building the program

25.6.2: Using `bisonc++' and `flexc++'

25.6.2.1: The `bisonc++' specification file

25.6.2.2: The `flexc++' specification file

25.6.2.3: Building the program