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Why C++?

What You Should Know Before..

you should be able to write C++ programs using components such as IOstreams and containers from C++ STL. You Should be also be familiar with the basic features of "Modern C++", such as auto, decltype, move semantics, and lambdas. c++17

modern C++

We will use number of these new features of modern C++

1. C++11

  • Variadic templates
  • Alias templates
  • Move semantics, rvalue references, and perfect forwarding
  • Standard type traits

2. C++14

  • Variable templates
  • Generic Lambdas

3. C++17

  • Class template argument deduction
  • Compile-time if
  • Fold expressions

Style Guide

1. the order of constant qualifier.

What is in front of const qualifier is always a constant

:+1:

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int const MAX_SIZE = 100; // the int is constant
int* const P; // the pointer cannot change, but int value can;

:-1:

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const int MAX_SIZE = 100; 
const int* P; // you can not find what's constant value;

reason1. easy to know what's constant. it's always what is in front of the const qualifier reason2. syntatical substitution principle. consider following example

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typedef char* CHARS;
typedef CHARS const CPTR; // constant pointer to chars
// => typedef char* const CPTR;

using CHARS = char*:
using CPTR = CHARS const; // constant pointer to chars
// => using CPTR = char* const;

The meaning of the second declaration is preseved when we textually replace CHARS with what it stands for; How ever if you write const before the type it qualifies. textually 

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typedef char* CHARS;
typedef const CHARS CTPR; //const pointer to chars;
// => typedef const char* CTPR // pointer to constant chars;
  • footnote: note that typedef defines a "type alias" rather than a new type
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typedef int newInt;
int i = 29;
newInt j = 1999;
i = j; // OK

2. put the space between the & and the parameter name;

by doing this, we emphasize the separation between the parameter type and the parameter name.

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void foo (int const& x);

3. avoid declaring multiple entities in this way!.

:-1:

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char* a, b;

according to the rules inherited from C, a is a pointer but b is an ordinary char;

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