[英]Linked-list with nested classes: how can I use nested class type before it is declared?
[英]How can I use a class before it is declared in c++?
我试图通过重载'='运算符为两个类创建一些转换函数。 这是一些代码:
class Vertex {
public:
int X, Y;
// .......
Vertex& operator= (const VertexF &); // ERROR, VertexF is not declared
};
class VertexF {
public:
float X, Y;
// ......
VertexF& operator= (const Vertex &);
};
我怎样才能做到这一点?
使用前瞻声明:
class VertexF; // forward declaration of VertexF
class Vertex {
public:
int X, Y;
// .......
Vertex& operator= (const VertexF &); // ERROR, VertexF is not declared
};
class VertexF {
public:
float X, Y;
// ......
VertexF& operator= (const Vertex &);
};
将类分隔为单独的文件,并使每个文件在其各自的头文件中引用另一个文件。
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