Re：在C ++中慢速手动'垃圾收集'？ [英] Re: Slow manual 'garbage collection' in C++ ??
问题描述
谢谢大家的回复！
我的确使用向量< vector< nDimensionalPoint *作为Hashtable。
我的要求是查找对于给定坐标，n维点的值非常快
。
我将尝试STL Map或Multiset。也许这样可以更快地运行并且更节省内存。
我之前从未听说过游泳池分配器，但谷歌也会这样做。
但是当我不在我的向量向量中使用指针但只有
向量< vector< nDimensionalPoint时，对象的析构函数
nDimensionalPoint被调用，我想？ br />
祝你好运！
Brey
荷兰
Thank you all for your replys !
Indeed I am using a vector<vector<nDimensionalPoint * as Hashtable.
My requirement is to lookup the value of a point of n dimensions very
fast for given coordinates.
I''m going to try an STL Map or Multiset. Maybe that works faster and
more memory efficient.
I have never heard before of a pool allocator but will Google for it.
But when I dont use pointers in my vector of vectors but only
vector<vector<nDimensionalPoint, the destructor of the objects
nDimensionalPoint are called, I suppose ?
Best regards !
Brey
The Netherlands
推荐答案
br ************* @ hotmail.com 写道：
谢谢大家的回复！
我确实使用了矢量< ; vector< nDimensionalPoint * as
Hashtable。我的要求是在给定坐标下非常快速地查找n
尺寸点的值。
我将尝试STL地图或多集。也许这样可以更快地运行并且更节省内存。
我之前从未听说过一个游泳池分配器，但谷歌会为它提供b
。 />
但是当我不在我的向量向量中使用指针而只有
向量< vector< nDimensionalPoint时，对象的析构函数
nDimensionalPoint被调用，我想？
Thank you all for your replys !
Indeed I am using a vector<vector<nDimensionalPoint * as
Hashtable. My requirement is to lookup the value of a point of n
dimensions very fast for given coordinates.
I''m going to try an STL Map or Multiset. Maybe that works faster and
more memory efficient.
I have never heard before of a pool allocator but will Google for
it.
But when I dont use pointers in my vector of vectors but only
vector<vector<nDimensionalPoint, the destructor of the objects
nDimensionalPoint are called, I suppose ?
是的，但是如果对象只包含双精度和整数，则析构函数
没有做任何事。不能比这快得多！
Bo Persson
Yes, but if the objects just contain doubles and ints, the destructor
doesn''t have to do anything. Can''t be much faster than that!
Bo Persson
17月17日，22：45，Bo Persson < b ... @ gmb.dkwrote：
On 17 jun, 22:45, "Bo Persson" <b...@gmb.dkwrote:
brey_maastri ... @ hotmail.com写道：
brey_maastri...@hotmail.com wrote:
谢谢大家的回复！
Thank you all for your replys !
我确实使用向量< vector< nDimensionalPoint *作为
Hashtable。我的要求是对给定坐标非常快速地查找n
维度的点的值。
Indeed I am using a vector<vector<nDimensionalPoint * as
Hashtable. My requirement is to lookup the value of a point of n
dimensions very fast for given coordinates.
我要尝试STL Map或Multiset。也许这样可以更快地运行并且更节省内存。
我之前从未听说过一个游泳池分配器，但谷歌会为它提供b
。
I''m going to try an STL Map or Multiset. Maybe that works faster and
more memory efficient.
I have never heard before of a pool allocator but will Google for
it.
但是当我在向量向量中不使用指针但只有
向量< vector< nDimensionalPoint时，析构函数为对象
nDimensionalPoint被调用，我想？
But when I dont use pointers in my vector of vectors but only
vector<vector<nDimensionalPoint, the destructor of the objects
nDimensionalPoint are called, I suppose ?
是的，但如果对象只包含双打和整数，则析构函数
不需要做任何事情。不能比这快得多！
Bo Persson
Yes, but if the objects just contain doubles and ints, the destructor
doesn''t have to do anything. Can''t be much faster than that!
Bo Persson
好吧，这些对象包含2个值和一个数组：
它的实际值，它的虚数值和一个整数的坐标
数组（因为坐标的数量必须是可变的，可以是2
维直到12维）。
所以我需要一个真正的析构函数来删除[] int数组。
Well, the objects contain 2 values and one array:
its real value, its imaginary value and the coordinates in an integer
array (because the number of coordinates have to be variable, can be 2
dimensional up till 12 dimensional).
So I need a real destructor which delete[] the int array.
6月17日，3：18 pm，brey_maastri ... @ hotmail.com写道：
On Jun 17, 3:18 pm, brey_maastri...@hotmail.com wrote:
>
好吧，这些对象包含2个值，一个数组：
它的实数值，它的虚数值和一个整数的坐标
数组（因为坐标的数量必须是可变的，可以是2
维直到12维）。
所以我需要一个真正的析构函数来删除[] int数组。
>
Well, the objects contain 2 values and one array:
its real value, its imaginary value and the coordinates in an integer
array (because the number of coordinates have to be variable, can be 2
dimensional up till 12 dimensional).
So I need a real destructor which delete[] the int array.
我想我在之前的帖子中说过这个，但我会再说一遍：如果
你需要使用一个变长数组，只需使用一个向量，比如
这个：
class nDimensionalPoint
{
public：
double realValue;
double imaginaryValue;
std :: vector< intcoordinates;
} ;
这样就没有必要定义一个析构函数，因为没有分配
的内存！
我希望这会有所帮助，Brey。
- Jean-Luc
I think I said this in my previous post, but I''ll say it again: If
you ever need to use a variable-length array, just use a vector, like
this:
class nDimensionalPoint
{
public:
double realValue;
double imaginaryValue;
std::vector<intcoordinates;
};
This way there''s no need do define a destructor, since there was no
memory allocated!
I hope this helps, Brey.
-- Jean-Luc
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