将非静态const数组声明为类成员

How can we declare a non-static const array as an attribute to class?

我们如何将非静态const数组声明为类的属性?

Following code produces compilation error

以下代码产生编译错误

'Test::x' : member could not be initialized

'test :: x':无法初始化成员

class Test
{
public:
    const int x[10];

public:
    Test()
    {
    }
};

3 个解决方案

#1

You should read this already posted question. Since it is not possible to do what you want, the workaround is to use an std::vector.

你应该阅读这个已发布的问题。由于不可能做你想要的,解决方法是使用std :: vector。

#2

You could use array class from tr1.

您可以使用tr1中的数组类。

class Test
{
public:
 const array<int, 10> x;

public:
 Test(array<int,10> val) : x(val) // the only place to initialize x since it is const
 {
 }
};

array class could be simplistically represented as follows:

数组类可以简单地表示如下:

template<typename T, int S>
class array
{
    T ar[S];
public:
    // constructors and operators
};

#3

Using boost::array (the same as tr1) it will looks like:

使用boost :: array(与tr1相同),它看起来像:

    #include<boost/array.hpp>

    class Test
    {   
       public:

        Test():constArray(staticConst) {}; 
        Test( boost::array<int,4> const& copyThisArray):constArray(copyThisArray) {}; 

        static const boost::array<int,4> staticConst; 

        const boost::array<int,4> constArray;
    };

    const boost::array<int,4> Test::staticConst = { { 1, 2, 3 ,5 } };

The extra code static member is needed because { { 1, 2, 3 ,5 } } is invalid in initialization list.

需要额外的代码静态成员,因为{{1,2,3,5}}在初始化列表中无效。

Some advantages is that boost::array have defined iterator and standard container methods like size, begin and end.

一些优点是boost :: array定义了迭代器和标准容器方法,如size,begin和end。

#1