这是否导致记忆泄露,wi住你的硬盘,使你怀孕,使纳萨尔人nas在你的公寓周围,或者让一切工作不明显问题,这是没有定义的。 这样做的方法可能是由一个汇编者进行,并与另一个汇编者进行改动,采用新的汇编版本,每一份新汇编,并附有月球阶段、你的 mo版,或者取决于最后一天下午通过加工商的内分因数。 也可能不是。

所有这一切,以及数量有限的其他可能性都包含在一个术语上:未界定的行为:

只是停留在它之外。

仅举例说明某些顾问和汇编者的一些“未界定”行为。 希望能够帮助人们改变其法典。

试验1

#include <iostream>
using namespace std;
int main()
{
  int *p = new int[5];
  cout << "pass" << endl;
  delete p;
  return 0;
}

试验2

#include <iostream>
using namespace std;
int main()
{
  int *p = new int;
  cout << "pass" << endl;
  delete[] p;
  return 0;
}

试验3

#include <iostream>
using namespace std;
struct C {
  C() { cout << "construct" << endl; }
  ~C() { cout << "destroy" << endl; }
};

int main()
{
  C *p = new C[5];
  cout << "pass" << endl;
  delete p;
  return 0;
}

试验4

#include <iostream>
using namespace std;
struct C {
  C() { cout << "construct" << endl; }
  ~C() { cout << "destroy" << endl; }
};

int main()
{
  C *p = new C;
  cout << "pass" << endl;
  delete[] p;
  return 0;
}

• Windows 7 x86, msvc 2010. Compile with default options, i.e. exception handler is enabled.

试验1

pass

试验2

pass

试验3

construct
construct
construct
construct
construct
pass
destroy
# Then, pop up crash msg

试验4

construct
pass
destroy
destroy
destroy
destroy
destroy
destroy
destroy
... # It never stop until CTRL+C

• Mac OS X 10.8.5, llvm-gcc 4.2 or gcc-4.8 generate the same output

试验1

pass

试验2

pass

试验3

construct
construct
construct
construct
construct
pass
destroy
a.out(71111) malloc: *** error for object 0x7f99c94000e8: pointer being freed was not allocated
*** set a breakpoint in malloc_error_break to debug
zsh: abort      ./a.out

试验4

construct
pass
a.out(71035) malloc: *** error for object 0x7f83c14000d8: pointer being freed was not allocated
*** set a breakpoint in malloc_error_break to debug
zsh: abort      ./a.out

• Ubuntu 12.04, AMD64, gcc 4.7

试验1

pass

试验2

pass

试验3

construct
construct
construct
construct
construct
*** glibc detected *** ./a.out: munmap_chunk(): invalid pointer: 0x0000000001f10018 ***
======= Backtrace: =========
/lib/x86_64-linux-gnu/libc.so.6(+0x7eb96)[0x7fe81d878b96]
./a.out[0x400a5b]
/lib/x86_64-linux-gnu/libc.so.6(__libc_start_main+0xed)[0x7fe81d81b76d]
./a.out[0x4008d9]
======= Memory map: ========
....
zsh: abort (core dumped)  ./a.out

试验4

construct
destroy
destroy
destroy
destroy
destroy
destroy
destroy
destroy
...
destroy
destroy
*** glibc detected *** ./a.out: free(): invalid pointer: 0x00000000016f6008 ***
======= Backtrace: =========
/lib/x86_64-linux-gnu/libc.so.6(+0x7eb96)[0x7fa9001fab96]
./a.out[0x400a18]
/lib/x86_64-linux-gnu/libc.so.6(__libc_start_main+0xed)[0x7fa90019d76d]
./a.out[0x4008d9]
======= Memory map: ========
...
zsh: abort (core dumped)  ./a.out

通常不会泄露,因为如果是POD destructors,就没有必要援引这些器具del。 记忆性交易只需要一点点值,才能将其归还给肥皂。 阵列还积存一个毗连的记忆组,因此,如果是单一元素的所在地,则会发生交易。