C++ 向量错误，无法让 push_back 工作
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/8216605/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
Vector error , cannot get push_back to work
提问by user1058359
This is just a snippet of the uncommented code. The packing vector keeps causing an error at the push_back(), and I'm not quite sure why:
这只是未注释代码的片段。打包向量在 处不断导致错误push_back()，我不太确定为什么：
EDIT:It has been updated to say
编辑：它已更新为
vector<BinTreeNode<HuffmanToken<Pixel>* > > packing = new vector<BinTreeNode<HuffmanToken<Pixel> > >();
however, there is still the allocator error even with the adjusted templates.
但是，即使使用调整后的模板，仍然存在分配器错误。
no matching function to call std::vector , std::allocator > > :: push_back(BinTreeNode > >&
没有匹配的函数来调用 std::vector ， std::allocator > > :: push_back(BinTreeNode > >&
BinTree<HuffmanToken<Pixel> >* Huffman::buildTree(const vector<HuffmanToken<Pixel>>& tokens) {
BinTreeNode<HuffmanToken<Pixel> >* g1 = new BinTreeNode<HuffmanToken<Pixel> >();
BinTreeNode<HuffmanToken<Pixel> >* g2 = new BinTreeNode<HuffmanToken<Pixel> >();
BinTreeNode<HuffmanToken<Pixel> >* g3 = new BinTreeNode<HuffmanToken<Pixel> >();
vector<HuffmanToken<Pixel> > packing ;
vector<HuffmanToken<Pixel> >::const_iterator it;
it = tokens.begin();
for(int i = 0; i < tokens.size(); i++) {
g1 -> setValue(tokens.at(i));
packing.push_back(g1);
}
回答by Ken Wayne VanderLinde
Your vector is expecting HuffmanToken<Pixel>objects, but you're trying to push_backa BinTreeNode<HuffmanToken<Pixel> >*pointer. Just make sure your vector has the right template type.
您的向量正在HuffmanToken<Pixel>等待对象，但您正在尝试指向push_back一个BinTreeNode<HuffmanToken<Pixel> >*指针。只需确保您的矢量具有正确的模板类型。
Edit
编辑
Considering your update, I decided to throw up all the code as it should be:
考虑到您的更新，我决定按原样扔掉所有代码：
BinTree<HuffmanToken<Pixel> >* Huffman::buildTree(const vector<HuffmanToken<Pixel>>& tokens) {
BinTreeNode<HuffmanToken<Pixel> >* g1 = new BinTreeNode<HuffmanToken<Pixel> >();
BinTreeNode<HuffmanToken<Pixel> >* g2 = new BinTreeNode<HuffmanToken<Pixel> >();
BinTreeNode<HuffmanToken<Pixel> >* g3 = new BinTreeNode<HuffmanToken<Pixel> >();
vector<BinTreeNode<HuffmanToken<Pixel> >*> packing ;
vector<BinTreeNode<HuffmanToken<Pixel> >*>::const_iterator it;
it = tokens.begin();
for(int i = 0; i < tokens.size(); i++) {
g1 -> setValue(tokens.at(i));
packing.push_back(g1);
}
The only difference from the original code is that vector<HuffmanToken<Pixel> >is replaced with vector<BinTreeNode<HuffmanToken<Pixel> >*>(that goes for the vectoritself, as well as the iterator).
与原始代码的唯一区别是vector<HuffmanToken<Pixel> >被替换为vector<BinTreeNode<HuffmanToken<Pixel> >*>(这适用于vector本身，以及迭代器)。
回答by David Schwartz
Your types don't match. You have a vector of HuffmanToken<Pixel>s and you're trying to push a BinTreeNode<HuffmanToken<Pixel> > *onto it.
你的类型不匹配。你有一个HuffmanToken<Pixel>s向量，你正试图将 a 推BinTreeNode<HuffmanToken<Pixel> > *到它上面。
回答by Mahesh
BinTreeNode<HuffmanToken<Pixel> >* g1 = new BinTreeNode<HuffmanToken<Pixel> >();
The type of g1is BinTreeNode<HuffmanToken<Pixel> >*i.e., it is a pointer type. But packingis of type vector<HuffmanToken<Pixel> >. What the vector holds is objects but not pointers to objects.
的类型g1是BinTreeNode<HuffmanToken<Pixel> >*即，它是一个指针类型。但packing属于vector<HuffmanToken<Pixel> >. vector 保存的是对象，而不是指向对象的指针。
回答by Victor Parmar
Your vector is of type HuffmanToken<Pixel>but you are trying to push type BinTreeNode<HuffmanToken<Pixel> >*into it.
您的矢量是有类型的，HuffmanToken<Pixel>但您正试图将类型推BinTreeNode<HuffmanToken<Pixel> >*入其中。
回答by cli_hlt
The problem here is that you are creating a vector that is supposed to hold items of type HuffmanToken<Pixel>. Instead of pushing items of that type into the vector, you try to push in a BinTreeNode<HuffmanToken<Pixel> >*.
这里的问题是您正在创建一个应该保存 type 项的向量HuffmanToken<Pixel>。您尝试将BinTreeNode<HuffmanToken<Pixel> >*.
And this cannot work.
这行不通。
What you probably wanted to push was the return value of g1->getValue()(if there is such a method at all...).
你可能想要推送的是g1->getValue()的返回值（如果有这样的方法......）。
