具有唯一键和值的 C# 字典类型 [英] C# dictionary type with unique keys and values

问题描述

我想知道 C# 中是否有类似于字典"的内置类型，但 TKey 和 TValue 必须是唯一的.

I was wondering if there was a built in type in C# that was like 'Dictionary' but where both TKey and TValue had to be unique.

例如::

d.Add(1, "1");
d.Add(2, "1"); // This would not be OK because "1" has already been used as a value.

我知道这有点奇怪，但似乎因为 BCL 中有大约 10 亿个集合类型，所以它可能存在.有什么想法吗?

I know this is kind of exotic, but it seems that since there are about a billion collection types in the BCL it might exist. Any ideas?

推荐答案

使用 Dictionary 和 HashSet/secondary reverse Dictionary 怎么样 - 它将解决问题并且比检查单个 Dictionary 的性能更好.

How about having Dictionary and HashSet/secondary reverse Dictionary - it will solve the issue and will perform better than checks on single Dictionary.

像这样，包装成类:

HashSet<string> secondary = new HashSet<string>(/*StringComparer.InvariantCultureIgnoreCase*/);
Dictionary<int, string>dictionary = new Dictionary<int, string>();
object syncer = new object();

public override void Add(int key, string value)
{
  lock(syncer)
  {
    if(dictionary.ContainsKey(key))
    {
      throw new Exception("Key already exists");
    }

    if(secondary.Add(value)
    {
      throw new Exception("Value already exists");
    }
    dictionary.Add(key, value);
  }
}

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