Use const whenever possible
One wonderful thing about const is that it allows you to specify a semantic constraint: a specific object should not be modified. The compiler will execute this constraint. It allows you to notify the compiler and other
Item 3: Use const whenever possible
By Scott Meyers
Translator: fatalerror99 (itepub's nirvana)
Release: http://blog.csdn.net/fatalerror99/
One wonderful thing about const is that it allows you to specify a semantic (semantic) Constraint: a specific
I. Possible combinations:
(1) const char * P
(2) Char const * P
(3) char * const P(4) const char ** P
(5) Char const ** P
(6) char * const * P
(7) Char ** const P
Of course, there are several cases of inserting a const in (5), (6), and
The use of const in C + + is very extensive, different location to use the meaning is not the same, so want to write an article to make a summary.
First of all, it is clear that the const is the basic meaning of "unchanging", but the same does not
Constraints for assigning values according to ansi c:
1. Both operands are pointers to compatible types with or without delimiters.
2. the type pointed to by the Left pointer must have all the qualifiers of the type pointed to by the right
1. Defining constants(1) The const modifier variable, the following two kinds of definition form are essentially the same. It means that the variable value of the type with the Const modifier is immutable.
TYPE const VALUENAME = value;
Seeing the const keyword, the first thing a C + + programmer might think of is a const constant. This is not a good reflex. If you only know to define constants with const, then it is equivalent to using gunpowder only to make firecrackers. The
One, possible combinations:(1) Const CHAR*P(2) Char Const*p(3) Char *const p(4) const char **P(5) Char Const**p(6) Char *const *p(7) Char **const pOf course, in (5), (6), (7) and then insert a const in a number of cases, but the analysis of the
Effective C + + Chapter 1. Make yourself accustomed to C + + (Accustoming yourself to C + +) Item 3. Use const (using const whenever possible) whenever possible1. Const and semantic constraintsconst allows you to specify a semantic constraint (that
Const thinking
1. What is const?A common type is a type described by the Type modifier Const. The values of variables or objects of a common type cannot be updated. (Of course, we can steal the bar for updating :)
2. Why is const introduced?The
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