Why can void * be a general pointer

First , The way void *  Previous solutions ：char * stay void Type acts as a general pointer before it comes out , however ASCII It specifies void keyword , Then for general pointers ,void * Instead of char *, But you can still use char * understand void * .

then , from   char * Analyze... From an angle , because char It is the most basic memory unit in a computer （8 bit）, So any other type is char Integer multiple , So any type of pointer is assigned to char * After that, it will be correctly truncated to the first memory address of the original type , And reinterpretation will not bring errors to the original data type .

Then come to the core principle ：

（1） During the life cycle of the original pointer ,  Convert it to char * Belongs to equal size conversion , in other words , The size of any pointer is equal .

（2）char *  What is saved is the first memory address of the original object , This value is equal to the value saved by the original pointer object .

（3） During the life cycle of the original pointer , Will be converted to char *  Re convert to the original pointer object , It will still be the original .

Come to a conclusion ：char * It can be used as a general pointer , void * It can be used as a general pointer .

 

tips： For pointer ,ANSI C The standard specifies its assignment constraints （ Include initialization ）：

1. Both operands are compatible pointers to finite determiners or infinite operators ;

2. The type pointed to by the pointer to the operand must have all qualifiers of the type pointed to by the right operand pointer （ The qualifier of the left operand can be more ）.