#include    <new>

class a
{
public:
    a();
};

a * pA;

void test()
{
    pA = new(std::nothrow) a;

}

  18:main.cpp      **** void test()
  19:main.cpp      **** {
100                      .loc 1 19 0
101                      .cfi_startproc
102                      @ args = 0, pretend = 0, frame = 0
103                      @ frame_needed = 0, uses_anonymous_args = 0
104 0000 10B5             push    {r4, lr}    @
105                  .LCFI0:
106                      .cfi_def_cfa_offset 8
107                      .cfi_offset 4, -8
108                      .cfi_offset 14, -4
  20:main.cpp      ****     pA = new(std::nothrow) a;
109                      .loc 1 20 0
110 0002 0549             ldr    r1, .L7    @,
111 0004 0120             movs    r0, #1    @,
112 0006 FFF7FEFF         bl    _ZnwjRKSt9nothrow_t    @  <-------- new(std::nothrow)
113                  .LVL0:
114 000a 0446             mov    r4, r0    @ D.8513,
115 000c 08B1             cbz    r0, .L2    @,                  <------- проверка
116                      .loc 1 20 0 is_stmt 0 discriminator 1
117 000e FFF7FEFF         bl    _ZN1aC1Ev    @           <------- вызов конструктора
118                  .LVL1:
119                  .L2:
120                      .loc 1 20 0 discriminator 4
121 0012 024B             ldr    r3, .L7+4    @ tmp112,
122 0014 1C60             str    r4, [r3]    @ D.8513, pA
123 0016 10BD             pop    {r4, pc}    @

int main(void)
{
EngineTask = new TEngineTask() ;
......

...........
class TEngineTask : public TTask
{
public:
TEngineTask ()
{
NOP();
active = false ;
NOP();
}
.........

398 __libc_init_array() ;
0800a82a: bl 0x800aec0 <__libc_init_array>
0800a82e: movs r0, #12 <-------- выхов main()
0800a830: bl 0x800a394 <malloc(size_t)> <-------- EngineTask = new TEngineTask() ;
0800a834: movs r5, #0 <-------- вызов конструктора
0800a836: ldr r3, [pc, #248] ; (0x800a930 <ResetHandler()+744>)
0800a838: str r3, [r0, #0]
0800a83a: str r5, [r0, #4]
0800a83c: nop
14 active = false ;
0800a83e: strb r5, [r0, #8]
15 NOP();
0800a840: nop
0800a842: ldr r3, [pc, #240] ; (0x800a934 <ResetHandler()+748>)

398 __libc_init_array() ;
0800a82a: bl 0x800aec4 <__libc_init_array>
0800a82e: movs r0, #12 <-------- выхов main()
0800a830: bl 0x800a394 <malloc(size_t)> <-------- EngineTask = new TEngineTask() ;
0800a834: cbz r0, 0x800a844 <ResetHandler()+508> <-------- проверка того что вернул malloc
12 {
0800a836: ldr r2, [pc, #252] ; (0x800a934 <ResetHandler()+748>) <- вызов конструктора
0800a83a: stmia.w r0, {r2, r3}
13 NOP();
0800a83e: nop
14 active = false ;
0800a840: strb r3, [r0, #8]
15 NOP();
0800a842: nop
0800a844: ldr r3, [pc, #240] ; (0x800a938 <ResetHandler()+752>)

EngineTask = new TEngineTask();

pA = new(std::nothrow) a;

                
void* __mem = malloc(sizeof(Packet));
if (__mem == nullptr)
{
        ...
}
else
{
    packet = new(__mem) Packet(...);
        ...

void* operator new(size_t size, void* p)
{
    (void) size;
    return p;
}

void* operator new(size_t, void* p)
{
    return p;
}

                
packet = new(std::nothrow) Packet;
if (packet == nullptr)
{
        ...
}
else
{
        ...