void pointer

/*** Device_create-creates a device and registers it with sysfs* @ Class: pointer to the struct class that this device shoshould be registered* @ Parent: pointer to the parent struct device of this new device, if any* @ Devt: The dev_t for the char device to be added* @ Drvdata: The data to be added to the device for callbacks* @ FMT: string for the device's name** This function can be used by char device c

When the parameter provided by a function is void *, pointer operations such as + 1 and-1 depend on the type of the actual variable. For example. Memcpy function, Void*Memcpy (Void * Dest,Const void * SRC,Size_t Count ); We can see that parameter 1 and 2 are all

syntax is used to declare an event member in a class: Public event indicates the name of the event. For example, if a click event member is declared in the control class, its syntax is as follows: Public event eventhandler click; In C #, a new data type delegate (representative) is added to solve the event processing problem. It indicates that the data type is very similar to the pointer in C language. What is different from the

The analysis principle of pointer variables: from the variable name, according to the operator priority combination, step-by-step analysis. ( the parentheses should be removed from the beginning of p )Pointer, point to what (x), X is what type ofInt *p; First, starting from P, first with *, that P is a pointer, and then combined with an int, indicating that the

So I changed the idea to understand this typedefLet's look at the general variable definition first:int int//defines a variable of type int named Int. Char *c//defines a char-type pointer variable void (*FUN) (void) named C;//defines a function pointer named fun, with a return value of

The three nouns, though very raozui, are very accurate. The semantic analysis of Chinese language can easily separate the three conceptual areas.A) constant pointer.Constants are adjectives, pointers are nouns, and pointers are the center of a partial positive structure phrase. In this way, a constant pointer is essentially a pointer, and a constant modifies it, indicating that the

Pointer function pointer array, function pointer Array Pointer variable analysis principle: Starting from the variable name, combined according to the operator priority, step by step analysis. (SlavePRemove the parentheses after the start.) Pointer, pointing to what (X), wha

Today in writing the project needs, use to void*, began not to understand what void* mean, asked the eldest, a language awakened dream of people!!!!!!Event->setuserdata ((void*) 10);int* data = (int*) event->getuserdata ();Cclog ("data =%d", data);Start so set Setuserdata, very puzzled why not *data can output 10, but *data on the error!!!!The boss said, the valu

, but the middle (void) (_x = = _y) is strange, what is the use of this sentence?Check the next network found:(void) (_x = = _y) This sentence itself from the implementation of the program is completely a nonsense, its role is that we can not do such operations typeof (_x) ==typeof (_y), so deliberately judged their 2 address pointers are equal, is obviously not equal, But if the type of _x and _y is differ

http://www.geeksforgeeks.org/g-fact-12-2/C allows a void* pointer to being assigned to any pointer type without a cast, whereas C + + does not; This idiomappears often in C code using malloc memory allocation. For example, the following are valid in C and not C + +: 1 void* ptr; 2 int *i = ptr; /* implicit conversion f

make the page does not jump. In href= "javascript:void (0)", a URI that begins with a javascript: protocol is used, and the browser defaults to the code after the colon, and then displays the result on the new page, except in one case, if the result is undefined, The browser will not refresh the page rendering new values. In fact, there are a number of ways to achieve the effect of a Hack, a collection that doesn't need to be in such a way-though it's really handy. JavaScript: The protocol d

? ------------------------------------------------You can directly jump to the corresponding memory physical address to runIt won't be as vague as above. C/C ++ code // ================================================ ==================/// Youlong bootloader loads the NK running entry function: the method of using the function pointer, // pretty clever, the program is more readable than the eboot of Samsung. ===========================

Recently, a friend jokingly asked if int *p * is a pointer or p is a pointer or *p is a pointer, of course, know that p is the pointerWild pointer----->>> refers to a pointer that does not point to an address (refer to the previous article for the

The name of the function is the first address of the function: The function pointer is defined, int (*p) (int) p is the function pointer variable name, int is the function's return value type int, and (int) is the parameter type of the function int type, note: Because of the priority so to use (*p), Otherwise, p is combined with the back () to int*p (int), which means that the return value of the P (int) fu

typedef void (*post_sync_t) (co_data*);The prototype of this function is void f (co_data*);After the typedef void (*post_sync_t) (co_data*), post_sync_t is the type alias of the pointer to the F-type function.At this point you can define a variable: post_sync_t p;,p is a pointer