C++:是否可以使用引用作为映射中的值?

2022-01-05 00:00:00 reference c++ map

是否可以在 C++ 中的标准地图容器中使用引用作为值?
如果没有 - 为什么不呢?

Is it possible to use a reference as the value in a standard map container in C++?
If not - why not?

示例声明:

map<int, SomeStruct&> map_num_to_struct;

示例用法:

...
SomeStruct* some_struct = new SomeStruct();
map_num_to_struct[3] = *some_struct;
map_num_to_struct[3].some_field = 14.3;
cout<<some_struct.some_field;
...

我希望看到 14.3 打印出来...

I would expect to see 14.3 printed...

推荐答案

没有.STL 容器值类型需要可赋值.引用不可分配.(你不能为它们分配一个不同的对象来引用.)

No. STL container value types need to be assignable. References are not assignable. (You cannot assign them a different object to reference.)

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