使用不同数据类型的C ++映射作为值 [英] C++ map with different data types as values

问题描述

我的问题如下：我想把两个（没有更多）不同的数据类型作为值映射到地图。

my problem is as follows: I want to put two (no more) different datatypes as values into a map.

typeX A, B, ...;
typeY Z, Y, ...;

void func (typeX) { ... }

void func (typeY) { ... }


std::map <std::string, what_to_put_here?? >map;
map["a"] = A;
map["z"] = Z;
...

std::vector<std::string> list;
//this list will be sth. like "a", "y", ...

for (unsigned int i = 0; i < list.size(); ++i)
    func( map[list[i]] )

显然这不起作用，因为地图只接受一种数据类型值。当循环list时，对func的调用应该是明确的，因为map [list [i]]的类型是已知的。

Obviously this doesn't work as the map will only accept one data type of value. When looping over "list", the call to "func" should be unambiguous since the type of map[list[i]] is known.

我想避免显式投放或类型检查，例如

I want to avoid explicit casting or typechecking, i.e. sth like

    if (typeid( map[list[i]] ).name() == "typeX")
        func( map[list[i]] )
    else if (typeid( map[list[i]] ).name() == "typeY")
        func( map[list[i]] )

你能告诉我这是否可能吗？同样，它将仅限于两种不同的数据类型。感谢！

Can you tell me if this is possible? Again, it will be limited to only two different data types. Thanks!

推荐答案

您要使用 boost :: variant ：

std::map <std::string, boost::variant<typeX, typeY>>

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