[英]c++ memory allocation vector of pointers
I am parallelizing code, thus using structure parallel_vector (ppl). 我正在并行化代码,因此使用结构parallel_vector(ppl)。 The question would be the same with standard std::vector...
问题与标准的std :: vector相同......
I first build a vectors of pointer to structs. 我首先构建一个指向结构的指针向量。 Struct is huge, with primitive types members alongside with huge arrays of primitive type (23000 elements).
结构是巨大的,原始类型成员与巨大的原始类型数组(23000个元素)一起。
I implemented a deep copy copy constructor for this struct. 我为这个结构实现了一个深拷贝拷贝构造函数。
Then, i access elements in this list in a loop. 然后,我循环访问此列表中的元素。
for (int ii=0; ii < nbBlocks; ii++)
{
MyStruct* Block_temp = list_structs.at( ii );
// ...
}
When i access element at position ii, am I creating a new object with memory allocation ? 当我访问位置ii的元素时,我是否创建了一个具有内存分配的新对象? should i delete Block_temp at the end of the current loop, or would this destroy the object that is contained in the vector ?
我应该删除当前循环结束时的Block_temp,还是会破坏向量中包含的对象?
Thanks 谢谢
You have a pointer to what is already in the vector, the vector seems to own your data, so do not delete it. 你有一个指向已经在向量中的内容的指针,向量似乎拥有你的数据,所以不要删除它。 Copying a pointer is not an allocation.
复制指针不是分配。
Consider: 考虑:
int* a = new int;
int* b = a; // Pretty much what you are doing
delete a; // If you deleted b, then this would be a double delete, and using a or b after that point would be bad
See the docs for std::vector::at 请参阅std :: vector :: at的文档
http://www.cplusplus.com/reference/vector/vector/at/ http://www.cplusplus.com/reference/vector/vector/at/
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