Introduction

• Purpose of the book: How to use c++ effectively.

  • 55 specific suggestions.

• Advice two categories

  • General design strategies
    • How to choose different approaches to accomplish something in c++.
    • Inheritance & templates
    • Private inheritance & composition
  • Nuts and bolts of specific language features
    • When should a destructor be virtual?
    • What happened when new can't find enough memory.

• Declaration
  • Tell compiler about the name and type of something, omit details.
• Definition
  • Provide compiler the details a declaration omits.
• Initialization
  • Give object its first value.
  • Constructor
    • Default constructor:
      • constructor can be called without parameters.
      • Either has no parameters or has default value for every parameters.
    • explicit constructor
      • Prevents them from being used to perform implicit type conversions by compilers.
        • E.g. implicit convert from int to class B.
          • B abc = 3 cause implicit conversion.
          • class B { B(int x=3) }
      • Preferable pattern.
  • Copy constructor
    • Initialize an object with a different object of same type.
    • Widget w3 = w2 is also a copy.
    • When function pass by value, copy constructor is called.
  • c.f. Copy assignment
    • copy value from one object to another existing object with same type.
    • Difference is whether it's a initialization.
• function objects
  • objects that act like functions.
  • a.k.a functor
• Undefined behavior
  • Behaviors of some constructs in C++ is undefined behavior.
  • Can't predict what happened at runtime.
  • E.g. dereference null pointer, invalid arr index.
• client
  • someone or something that use the code you write.
    • Maybe code or developer that write client code.