Question

我无法将阵列推入堆栈。我觉得这很简单，但我已经花了太多时间试图弄清楚这一点。

我希望能够像推入或浮动一样推送数组，但这种情况不会发生。

push命令给了我这个问题。这是我的代码：

#include <iostream>
#include <stack>

struct Matrix4x4
{
  float data[16];
};


int main(int argc, char **argv) 
{
// My original code
typedef std::stack<float[16]> myStack;
myStack modelViewStack;
myStack projectionStack;
float testMat[16] = {0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15};

modelViewStack.push(testMat); // THIS LINE GIVES ME ERRORS




////Stack initialization - This is thokra's solution
////typedef std::stack<std::vector<float[16]>> myStack;
//typedef std::stack<Matrix4x4> myStack;
//myStack modelViewStack;
//myStack projectionStack;

//
//Matrix4x4 m = {0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15};
////std::vector<float> testMat2(testMat, testMat + sizeof(testMat) / sizeof(float));

//modelViewStack.push(m);

//for(int i = 0; i<16 ; i++)
//{
//  std::cout << "m data: " << m.data[i] << std::endl;
//}
//system("pause");

return 0;

}

感谢您的帮助！

以下是错误。我无法解读它们。也许对如何阅读这些内容的解释也会有所帮助。

1>------ Build started: Project: opengl4_4, Configuration: Release Win32 ------
1>  main.cpp
1>C:\Program Files (x86)\Microsoft Visual Studio 11.0\VC\include\xmemory0(606): error C2075: 'Target of operator new()' : array initialization needs curly braces
1>          C:\Program Files (x86)\Microsoft Visual Studio 11.0\VC\include\xmemory0(605) : while compiling class template member function 'void std::allocator<_Ty>::construct(_Ty (*),const _Ty (&))'
1>          with
1>          [
1>              _Ty=float [16]
1>          ]
1>          C:\Program Files (x86)\Microsoft Visual Studio 11.0\VC\include\xmemory0(751) : see reference to function template instantiation 'void std::allocator<_Ty>::construct(_Ty (*),const _Ty (&))' being compiled
1>          with
1>          [
1>              _Ty=float [16]
1>          ]
1>          C:\Program Files (x86)\Microsoft Visual Studio 11.0\VC\include\type_traits(743) : see reference to class template instantiation 'std::allocator<_Ty>' being compiled
1>          with
1>          [
1>              _Ty=float [16]
1>          ]
1>          C:\Program Files (x86)\Microsoft Visual Studio 11.0\VC\include\deque(925) : see reference to class template instantiation 'std::is_empty<_Ty>' being compiled
1>          with
1>          [
1>              _Ty=std::allocator<float [16]>
1>          ]
1>          C:\Program Files (x86)\Microsoft Visual Studio 11.0\VC\include\stack(21) : see reference to class template instantiation 'std::deque<_Ty>' being compiled
1>          with
1>          [
1>              _Ty=float [16]
1>          ]
1>          main.cpp(14) : see reference to class template instantiation 'std::stack<_Ty>' being compiled
1>          with
1>          [
1>              _Ty=float [16]
1>          ]
1>C:\Program Files (x86)\Microsoft Visual Studio 11.0\VC\include\xmemory0(606): fatal error C1903: unable to recover from previous error(s); stopping compilation
========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ==========

Answer 1

只需将包含矩阵元素的数据存储封装在合适的类型中：

#include <stack>    
struct Matrix4x4
{
  float data[16];
};

int main()
{
  typedef std::stack<Matrix4x4> myStack;
  myStack modelViewStack;
  Matrix4x4 m = {0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15};
  modelViewStack.push(m);
  return 0;
}

更重要的是：当您不更改默认值时，std::stack::push会在push_back内部调用用作容器的std::deque。实质上，当试图在deque的末尾构造一个新元素时，容器会尝试将新元素放在当前用展示位置标记容器末尾的地址 - new。例如，g ++按如下方式实现它：

template<typename _Up, typename... _Args>
  void
  construct(_Up* __p, _Args&&... __args)
{ ::new((void *)__p) _Up(std::forward<_Args>(__args)...); }

这实际上归结为：

::new((void *)__p) float[16](_args); // where __p is a pointer to float[16] and _args is testMat

尝试复制或移动初始化C阵列根本就不合法。即使由于某种原因构造成功，容器也会在超出范围时尝试在类型float[16]的元素上调用析构函数。人们可以很容易地看到，析构函数~T[n]不存在。

在C ++ 11中，您可以push一个std::array<float,16>而不是定义其他类型。

C ++标准库堆栈用法。麻烦推浮阵列

1 个答案: