Д>Немного нагляднее и короче, чем ZeroMemory. Хоть это и небольшой хак

mov         dword ptr [ebp-7Ch],0
mov         ecx,1Dh
xor         eax,eax
lea         edi,[ebp-78h]
rep stos    dword ptr [edi]
stos        word ptr [edi]
stos        byte ptr [edi]

> Д>Немного нагляднее и короче, чем ZeroMemory. Хоть это и небольшой хак

8.5.1/7 If there are fewer initializers in the list than there are members in the aggregate, then each member not explicitly initialized shall be value-initialized (8.5). [Example:

   struct S { int a; char* b; int c; };
   S ss = { 1, "asdf" };

initializes ss.a with 1, ss.b with "asdf", and ss.c with the value of an expression of the form
int(), that is, 0. ]

int аrr[10] = {};

#include <iostream>
#include <string>

using namespace std;

struct SomeStruct
{
    int    i;
    string    s;
};

int main()
{
    SomeStruct ss /* = { 100 } */ ;

    ss.i = 5;
    cout << "ss.i:          " << ss.i       << endl
         << "ss.s.length(): " << ss.s.length() << endl;

    return 0;
}

ПК>Хорошо, уговорил. Используй Только другим не навязывай.

> struct SomeStruct
> {
>     int    i;
>     string    s;
> };
>
>     SomeStruct ss /* = { 100 } */ ;
>

struct SomeStruct
{
   int i;
   const char* s;
};
...
SomeStruct s;
ZeroMemory(&s, sizeof(s));

SomeStruct s = SomeStruct();

SomeStruct s = { 0 };

SomeStruct s = { };

> ПК>Хорошо, уговорил. Используй Только другим не навязывай.

Лучше использовать ZeroMemory()

> PPS. У Вас, Павел, указан неверный автор цитаты!

ПК>struct SomeStruct
ПК>{
ПК>   int i;
ПК>   const char* s;
ПК>};
ПК>...
ПК>SomeStruct s;
ПК>ZeroMemory(&s, sizeof(s));
ПК>

struct packet {
       unsigned short packet_len;
       unsigned short flags;
       union {
                char  text[100];
                ...
       } u;
       ...
       char     reserved[8]; /* must be zero */
} packet;

Д>Немного нагляднее и короче, чем ZeroMemory. Хоть это и небольшой хак

HANDLE hHeap = GetProcessHeap();
MSG *pMsg = (MSG*) HeapAlloc(hHeap, HEAP_ZERO_MEMORY, sizeof(MSG));
//...
HeapFree(hHeap, 0, pMsg);

maq>ИМХО бред какой то?

//MAPIWin.h
#if !defined(_WIN32)
#define    ZeroMemory(pb,cb)            memset((pb),0,(cb))
#endif

//WinBase.h
#define ZeroMemory RtlZeroMemory

WNDCLASSEX wc={sizeof(WNDCLASSEX)};

MN>//MAPIWin.h
MN>#if !defined(_WIN32)
MN>#define    ZeroMemory(pb,cb)            memset((pb),0,(cb))
MN>#endif

MN>//WinBase.h
MN>#define ZeroMemory RtlZeroMemory
MN>

//WinNt.h
#if defined(_M_AMD64)
...
#else
#define RtlZeroMemory(Destination,Length) memset((Destination),0,(Length))
#endif

MN>>//MAPIWin.h
MN>>#if !defined(_WIN32)
MN>>#define    ZeroMemory(pb,cb)            memset((pb),0,(cb))
MN>>#endif

MN>>//WinBase.h
MN>>#define ZeroMemory RtlZeroMemory
MN>>

MS>//WinNt.h
MS>#if defined(_M_AMD64)
MS>...
MS>#else
MS>#define RtlZeroMemory(Destination,Length) memset((Destination),0,(Length))
MS>#endif
MS>

#if defined(_M_AMD64) || defined(_M_IA64)
NTSYSAPI
VOID
NTAPI
RtlZeroMemory (
   VOID UNALIGNED *Destination,
   SIZE_T Length
   );

#else
#define RtlZeroMemory(Destination,Length) memset((Destination),0,(Length))
#endif

 P> WNDCLASSEX wc={sizeof(WNDCLASSEX)};
 P>

P>

WNDCLASSEX ext_data = { sizeof(ext_data) };

int x=int();

int x;

memset(&x,0,sizeof x);

wcx = WNDCLASSEX();

MN>>Или вы поможете Microsoft переписать все эти исходники?

так и RtlZeroMemory

/* item.h */
struct item;

struct item *allocitem(void);

/* item.c */
#include "item.h"

struct item  {
    double f;
    const void *ptr;
};

static struct item inititem(struct item *item)
{
    static const struct item initer =  {
        .0,           /* .item */
        (void*) NULL  /* .ptr */
    };
    if(item != NULL)  {
        *item = initer;
    }
    return item;
}

struct item *allocitem(void)
{
    return inititem(malloc(sizeof(struct item)));
}

Struct s = { 0 };

Struct s = Struct();

some_class::some_class() {
    ZeroMemory( this, sizeof( this ) );
}

MyStruct s = MyStruct();

#include <iostream>

struct MyStruct
{
   int i;
   int j;
};

int main()
{
   MyStruct s = MyStruct();
   std::cout << s.i << ", " << s.j << std::endl;
}

C:\Prg\Microsoft\Visual C++ Toolkit 2003\bin>cl.exe -GX main.cpp
Microsoft (R) 32-bit C/C++ Optimizing Compiler Version 13.10.3052 for 80x86
Copyright (C) Microsoft Corporation 1984-2002. All rights reserved.

main.cpp
Microsoft (R) Incremental Linker Version 7.10.3052
Copyright (C) Microsoft Corporation.  All rights reserved.

/out:main.exe
main.obj


C:\Prg\Microsoft\Visual C++ Toolkit 2003\bin>main
0, 0

_s$ = -8                        ; size = 8

; 11   :    MyStruct s = MyStruct();

    xor    eax, eax
    mov    DWORD PTR $T10428[ebp], eax
    mov    DWORD PTR $T10428[ebp+4], eax
    mov    ecx, DWORD PTR $T10428[ebp]
    mov    DWORD PTR _s$[ebp], ecx
    mov    edx, DWORD PTR $T10428[ebp+4]
    mov    DWORD PTR _s$[ebp+4], edx

; 12   :    std::cout << s.i << ", " << s.j << std::endl;

    push    OFFSET FLAT:?endl@std@@YAAAV?$basic_ostream@DU?$char_traits@D@std@@@1@AAV21@@Z ; std::endl
    mov    eax, DWORD PTR _s$[ebp+4]
    push    eax
    push    OFFSET FLAT:$SG8481
    mov    ecx, DWORD PTR _s$[ebp]
    push    ecx
    mov    ecx, OFFSET FLAT:?cout@std@@3V?$basic_ostream@DU?$char_traits@D@std@@@1@A
    call    ??6?$basic_ostream@DU?$char_traits@D@std@@@std@@QAEAAV01@H@Z ; std::basic_ostream<char,std::char_traits<char> >::operator<<

; 11   :    MyStruct s = MyStruct();

    xor    eax, eax

; 12   :    std::cout << s.i << ", " << s.j << std::endl;

    push    eax
    mov    ecx, eax
    push    OFFSET FLAT:??_C@_02KEGNLNML@?0?5?$AA@
    push    ecx
    mov    ecx, OFFSET FLAT:?cout@std@@3V?$basic_ostream@DU?$char_traits@D@std@@@1@A
    call    ??6?$basic_ostream@DU?$char_traits@D@std@@@std@@QAEAAV01@H@Z ; std::basic_ostream<char,std::char_traits<char> >::operator<<

ПК>#include <iostream>

ПК>struct MyStruct
ПК>{
ПК>   int i;
ПК>   int j;
ПК>};

ПК>int main()
ПК>{
ПК>   MyStruct s = MyStruct();
ПК>   std::cout << s.i << ", " << s.j << std::endl;
ПК>}
ПК>

#include <iostream>

struct A{
  int a;
};

struct B : public A{
  int b;
};

int main()
{
   B b = B();
   std::cout << b.a << "," << b.b << std::endl;
   return 0;
}