Accustoming Yourself to C++

Terms 01: as C ++ is a language federal

View C++ as a federation of languages.

• Efficient C ++ Programming Code, as the situation varies, depending on which part of your use of C ++.

Terms 02: try to const, enum, inline replace #define

Preper consts,enums and inlines to #defines.

• For simple constants, or preferably in const object enums replaced #defines.
• For the shape of a macro function (macros), preferably use the inline function replacement #defines.

Both can be used to define and const define a constant, but when const definition defines the type of constants, the more accurate number. #define simply text replacement, in addition to define constants, but can also be used to define some simple functions, somewhat similar to inline (Inline).

Terms 03: Whenever possible, use const

Use const whenever possible.

• Some things will be const help the compiler can detect errors usage. Const objects may be applied to any of scope, function arguments, return type of the function, the function of the body member.
• The compiler enforces bitwise constness, but you should use the "constants of the conceptual" (conceptual constness) when writing programs.
• When const and non-const member functions has achieved substantial equivalents, so that non-const version call the const version avoids code duplication.

const Usage:

• const and pointers

  int a = 5;
  int * const p = & a; // pointer constant
   const int * p = & a; // constant pointer
  

• const reference
  const reference point corresponding to the variable const const pointer, which points to the point, and the contents are allowed to change. So when the function returns a const reference, not by the function returns a reference to the actual object to make any changes.

• const and function
  1, const Return Value modification: a function call that can not be used as an expression value left.
  2, const modified parameters: the parameter passed in the function can not be changed.
  3, const function: Any attempt to change the member variables and call non-const member functions of operation are considered illegal.

• const and class/
  1, const initialization data member can only be performed in the initialization table constructor of the class;
  2, const const object can only invoke a function as an ordinary function may modify a member variable. (Ordinary objects can either call the const function, you can also call ordinary function.)

Terms 04: determine before the object is first initialized using

Make sure that objects are initialized before they’re used.

• Manual initialization is built-in objects, because C ++ does not guarantee initialize them.
• Constructor is preferable to use the initial value column member (member initialization list), rather than using an assignment operator (Assignment) constructor body. The initial value of the member variable column lists, order over and they should be declared in the same order in class.
• For the removal of "cross-compilation unit of the initialization order" problem, replace the non-local static objects with local static objects.

Reference article:
《Effective C++》
C ++ usage at different locations in the const
C ++ inline functions (C ++ inline) Explanation