Const Small summary of C + + (3)

Const Small summary of C + + (2)

Today, we discuss the relationship between a pointer or a referenced shape participating in a const.

First of all: in C + +, the parameters of the same name function must be clearly distinguished.

For example, a function with the same name as void reset (int &i) and void reset (const int &i) is not compiled.

 int  i = 0   const  int  ci = I;  string :: Size_type ctr = 0  ;reset ( &i); Reset ( &ci); //  error, cannot be initialized with a pointer to a const int object int*  reset (i); reset (CI);  //  error, cannot bind ordinary reference to const object CI on  reset (42 ); //  error, cannot bind ordinary reference to literal value  Reset (CTR); //  error, type mismatch, str is unsigned type  

We can see that there are many limitations when using a function without constant reference.

There are two drawbacks to using normal references in functions that do not change the parameters:

1. The user of a function is misleading: a function can modify the value of its argument.
2. Greatly restricts the types of arguments that a function can accept. We cannot pass const objects, literals, or objects that require type conversions to ordinary reference arguments.

We'll get this sorted out today.

Const Small summary of C + + (3)