现在,我想用一个函数来增加数组的大小。尝试在C++中动态调整数组大小时崩溃?
#include <iostream>
using namespace std;
void IncreaseArraySize(int* addr){
int* temp = new int[20];
for(int i=0;i<10;i++){
temp[i] = addr[i];
}
for(int i=10;i<20;i++){
temp[i] = i;
}
int* dummy = addr;
addr = temp;
delete[] dummy;
}
int main(){
int* test = new int[10];
for(int i=0;i<10;i++){
test[i] = i;
}
IncreaseArraySize(test);
for(int i=0;i<20;i++){
cout<<"at index "<<i<<"we have"<<test[i]<<endl;
}
cout<<"ok!"<<endl;
delete[] test;
}
我跑的代码: 的valgrind --leak检查=全./test 2> DEBUG.TXT
,这是我得到的输出:
at index 0we have0
at index 1we have1
at index 2we have2
at index 3we have3
at index 4we have4
at index 5we have5
at index 6we have6
at index 7we have7
at index 8we have8
at index 9we have9
at index 10we have0
at index 11we have0
at index 12we have0
at index 13we have0
at index 14we have0
at index 15we have0
at index 16we have0
at index 17we have0
at index 18we have112
at index 19we have0
ok!
,这就是我在DEBUG.TXT有:
==4285== Memcheck, a memory error detector
==4285== Copyright (C) 2002-2010, and GNU GPL'd, by Julian Seward et al.
==4285== Using Valgrind-3.6.1-Debian and LibVEX; rerun with -h for copyright info
==4285== Command: ./test
==4285==
==4285== Invalid read of size 4
==4285== at 0x400997: main (test.cpp:24)
==4285== Address 0x596f040 is 0 bytes inside a block of size 40 free'd
==4285== at 0x4C27C6E: operator delete[](void*) (vg_replace_malloc.c:409)
==4285== by 0x400931: IncreaseArraySize(int*) (test.cpp:14)
==4285== by 0x400980: main (test.cpp:22)
==4285==
==4285== Invalid free()/delete/delete[]
==4285== at 0x4C27C6E: operator delete[](void*) (vg_replace_malloc.c:409)
==4285== by 0x400A16: main (test.cpp:27)
==4285== Address 0x596f040 is 0 bytes inside a block of size 40 free'd
==4285== at 0x4C27C6E: operator delete[](void*) (vg_replace_malloc.c:409)
==4285== by 0x400931: IncreaseArraySize(int*) (test.cpp:14)
==4285== by 0x400980: main (test.cpp:22)
==4285==
==4285==
==4285== HEAP SUMMARY:
==4285== in use at exit: 80 bytes in 1 blocks
==4285== total heap usage: 2 allocs, 2 frees, 120 bytes allocated
==4285==
==4285== 80 bytes in 1 blocks are definitely lost in loss record 1 of 1
==4285== at 0x4C2864B: operator new[](unsigned long) (vg_replace_malloc.c:305)
==4285== by 0x4008A9: IncreaseArraySize(int*) (test.cpp:5)
==4285== by 0x400980: main (test.cpp:22)
==4285==
==4285== LEAK SUMMARY:
==4285== definitely lost: 80 bytes in 1 blocks
==4285== indirectly lost: 0 bytes in 0 blocks
==4285== possibly lost: 0 bytes in 0 blocks
==4285== still reachable: 0 bytes in 0 blocks
==4285== suppressed: 0 bytes in 0 blocks
==4285==
==4285== For counts of detected and suppressed errors, rerun with: -v
==4285== ERROR SUMMARY: 22 errors from 3 contexts (suppressed: 4 from 4)
你能在新手来解释这一切?
这可能会有帮助:http://stackoverflow.com/q/9167540/535275 – 2012-02-07 02:51:35
'addr = temp;'不会做你认为它做的事。 – 2012-02-07 02:53:14
我以为addr = temp应该复制temp所持有的东西(因为temp是一个指针,地址到一些堆空间)addr ...猜C++对我来说太困难 – user269334 2012-02-07 05:27:24