blocks|key|1777590|text|Record<any,+any>是一个类型，而Map<any,+any>是一个“扩展”Record的值，当您传递一个Map值时，第一个签名与第一个调用是一致的，这就是为什么类型记录看到dostuff(Record<any,+any>)调用正确返回Record<any,+any>的原因。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1777591|由于上述原因，Record不能分配给Map，这就是为什么类型记录会引发错误。|1777592|您应该只使用Record或Map过载|1777593|entityMap^0|0|G|N|D|17|6|1M|3|2K|P|3F|G|0|7|6|I|3|0|6|6|D|3|0^^$0|@$1|2|3|4|5|6|7|L|8|@$9|M|A|N|B|C]|$9|O|A|P|B|C]|$9|Q|A|R|B|C]|$9|S|A|T|B|C]|$9|U|A|V|B|C]|$9|W|A|X|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|Y|8|@$9|Z|A|10|B|C]|$9|11|A|12|B|C]]|D|@]|E|$]]|$1|H|3|I|5|6|7|13|8|@$9|14|A|15|B|C]|$9|16|A|17|B|C]]|D|@]|E|$]]|$1|J|3|-4|5|6|7|18|8|@]|D|@]|E|$]]]|K|$]]

<code>Record&lt;any, any&gt;</code> is a type, while <code>Map&lt;any, any&gt;</code> is a value that &quot;extends&quot; <code>Record</code>, when you pass a <code>Map</code> value the first signature that coincides whit the call is the first one, and that's why Typescript see a call of <code>dostuff(Record&lt;any, any&gt;)</code> correctly returning a <code>Record&lt;any, any&gt;</code>.
<code>Record</code> is not assignable to <code>Map</code> for the reason above, this is why Typescript raise an error.
You should overload with just <code>Record</code> or <code>Map</code>

blocks|key|1789455|text|TL;DR:您需要像这样交换您的两个呼叫签名：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1789456|function+doStuff(arg:+Map<any,+any>):+Map<any,+any>;
function+doStuff(arg:+Record<any,+any>):+Record<any,+any>;
function+doStuff(arg:+any)+{
++return+arg;
}|code-block|syntax|javascript|1789457|类型Record<any,+any>+(使用实用程序类型)等同于{[x:+string]:+any}|offset|length|style|CODE|1789458|type+RecordAnyAny+=+Record<any,+any>;
//+type+RecordAnyAny+=+{[x:+string]:+any}|1789459|具有string+索引签名的类似对象的类型，其属性为类型。所以它可以有任何键和任何值。因此，几乎任何对象都可以分配给它：|1789460|let+r:+RecordAnyAny
r+=+{};+//+okay
r+=+{a:+0,+b:+"one",+c:+true};+//+okay
r+=+new+Date();+//+okay;
r+=+new+Map();+//+okay,+note+well|1789461|正如您所看到的，即使是对象也可以分配给Record<any,+any>。|1789462|另一方面，Map<K,+V>类型是在TypeScript库中定义，如下所示：|1789463|interface+Map<K,+V>+{
++++clear():+void;
++++delete(key:+K):+boolean;
++++forEach(callbackfn:+(value:+V,+key:+K,+map:+Map<K,+V>)+=>+void,+thisArg?:+any):+void;
++++get(key:+K):+V+%7C+undefined;
++++has(key:+K):+boolean;
++++set(key:+K,+value:+V):+this;
++++readonly+size:+number;
}|1789464|Map<any,+any>与any的接口等价于K和V。|1789465|这种类型比Record<any,+any>具有更强的限制性。如果我有一个类型为m的值，我知道它将有一个get()方法，但是对于Record<any,+any>，我不知道，所以使用Record<any,+any>作为Map<any,+any>是不安全的(尽管反向操作是安全的)：|1789466|let+m:+Map<any,+any>+=+new+Map();
m+=+r;+//+error
//+Type+'RecordAnyAny'+is+missing+the+following+properties+from
//++type+'Map<any,+any>':+clear,+delete,+forEach,+get,+and+8+more.(2740)|1789467|因此，希望这是明确的:每个Map<any,+any>都是一个Record<any,+any>，但不是每个Record<any,+any>都是一个Map<any,+any>。|1789468|现在我们可以看看你的过载函数|1789469|//+call+signatures+
function+doStuffOld(arg:+Record<any,+any>):+Record<any,+any>;
function+doStuffOld(arg:+Map<any,+any>):+Map<any,+any>;

//+implementation
function+doStuffOld(arg:+any)+{
++return+arg;
}

doStuffOld(new+Map<any,+any>());|1789470|调用重载函数时，编译器将选择第一个匹配的调用签名。因此，对于doStuffOld(new+Map<any,+any>())，编译器将检查第一个调用签名(arg:+Record<any,+any>)+=>+Record<any,+any>。它工作吗？是的。每个May<any,+any>也是一个Record<any,+any>，所以编译器选择这个重载。因此返回类型也是Record<any,+any>，将结果赋值给Map<any,+any>是一个错误|BOLD|1789471|m+=+doStuffOld(new+Map<any,+any>());+//+error!|1789472|第二个呼叫签名从未到达。糟了。|1789473|因为Map<any,+any>比Record<any,+any>更具体，所以需要交换两个调用签名的顺序。这个建议也在TypeScript手册中功能过载的Do和请勿中给出。|1789474|//+call+signatures
function+doStuff(arg:+Map<any,+any>):+Map<any,+any>;
function+doStuff(arg:+Record<any,+any>):+Record<any,+any>;

//+implementation
function+doStuff(arg:+any)+{
++return+arg;
}

m+=+doStuff(new+Map<any,+any>());+//+okay
r+=+doStuff({a:+0,+b:+"one",+c:+true});+//+okay|1789475|现在，当您调用doStuff(new+Map<any,+any>())时，编译器首先尝试Map调用签名。这是匹配的，所以您将得到Map返回类型。|1789476|当您调用doStuff({a:+0,+b:+"one",+c:+true})时，编译器尝试Map调用签名，但它不匹配(因为该对象不是Map)，因此它会尝试Record调用签名，该签名确实匹配.然后得到Record返回类型。|1789477|因此，现在一切都应该按需要运作。|1789478|操场链接到代码|1789479|entityMap|0|LINK|mutability|MUTABLE|url|https://www.typescriptlang.org/docs/handbook/utility-types.html#recordkeystype|1|https://www.typescriptlang.org/docs/handbook/2/objects.html#index-signatures|2|https://www.typescriptlang.org/docs/handbook/2/everyday-types.html#any|3|https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Map|4|https://github.com/microsoft/TypeScript/blob/6834969f8f20d0cf64a40cc8d146a1be3d5440b0/lib/lib.es2015.collection.d.ts#L21-L29|5|https://www.typescriptlang.org/docs/handbook/2/functions.html#function-overloads|6|https://www.typescriptlang.org/docs/handbook/declaration-files/do-s-and-don-ts.html#ordering|7|https://www.typescriptlang.org/play?ts=4.6.2#code/C4TwDgpgBAShDGB7ATgEwIIDsRZFAvLAiqgDwCG2ANFJSAHwDcAUAPStSiRFJq64EoAbwDaADwBcUAM7BkAS0wBzALpS6AX2bMANhGBRkUuLwzZczZIKEbGUdlEQBrciEvXyUgAw0ARlIAiREwIAJp4KTkAVwhbew5nV3dCEIB3KAARcmAIAAoASjsHRJAWKxSIdIBZcjACooSXN119KABbKRqwCmpabHpBNKgu%2BuY2wWQGqAhkZBQ2DgAVcGgAchMSfmxVqHlpdr3pRSVOAAtoADNEHR1EVOOoMDnIZGB5CH2LubaFqE4VqCrLo9EA0Oj0VZSeB6cjIGioCB6HI0K7IACi5HgpxoSn0YMwqCgAA52igIAA6XIAJgA7AAWLz5bS-eDkG4yeRKTDZKLID5QZgXKKYeBvYJQVCIADKwCiFwuAHkdKhcrClMZiGgQfiGPkNaZtX0GCwhSKxZgJdLZfKlSq1Z1aobwXrho66DqmL95G0wHo2hBMMBsvJgoLhaKQxbJTK5YrlarkOqjflhMw-nzZcgLWqWFoxoJo9a4yqhsD3Ub6AVCvFprMUABCZmmiPiwuxhNJsu9Z0O7rl8Em8Pmy0x%2BUd-UkJ39F0bLX9-qDs2RkdF8fJ1Pp-S87OJ3PacaENtj0tu7v9KtTErJFftoSeKA%2BKD%2BKBBEJhKARTjIGIaavFJrMkAA^0|0|0|2|G|W|I|M|6|0|0|0|2|6|9|4|1|Q|2|2|0|0|J|G|B|2|3|0|5|9|H|F|4|0|0|0|D|E|3|N|1|P|1|0|5|G|13|1|1F|5|1R|G|2H|G|2Z|D|0|0|D|D|U|G|1G|G|20|D|0|A|4|5|0|0|U|V|23|17|3L|D|42|G|53|G|5Q|D|3G|3|0|0|0|2|D|G|G|1M|N|6|0|0|7|S|18|3|1S|3|0|4|Y|19|3|1U|3|25|6|2S|6|0|0|0|7|7|0^^$0|@$1|2|3|4|5|6|7|2F|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|2G|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|2H|8|@$I|2I|J|2J|K|L]|$I|2K|J|2L|K|L]]|9|@$I|2M|J|2N|1|2O]]|A|$]]|$1|M|3|N|5|D|7|2P|8|@]|9|@]|A|$E|F]]|$1|O|3|P|5|6|7|2Q|8|@$I|2R|J|2S|K|L]]|9|@$I|2T|J|2U|1|2V]|$I|2W|J|2X|1|2Y]]|A|$]]|$1|Q|3|R|5|D|7|2Z|8|@]|9|@]|A|$E|F]]|$1|S|3|T|5|6|7|30|8|@$I|31|J|32|K|L]]|9|@$I|33|J|34|1|35]]|A|$]]|$1|U|3|V|5|6|7|36|8|@$I|37|J|38|K|L]]|9|@$I|39|J|3A|1|3B]]|A|$]]|$1|W|3|X|5|D|7|3C|8|@]|9|@]|A|$E|F]]|$1|Y|3|Z|5|6|7|3D|8|@$I|3E|J|3F|K|L]|$I|3G|J|3H|K|L]|$I|3I|J|3J|K|L]|$I|3K|J|3L|K|L]]|9|@]|A|$]]|$1|10|3|11|5|6|7|3M|8|@$I|3N|J|3O|K|L]|$I|3P|J|3Q|K|L]|$I|3R|J|3S|K|L]|$I|3T|J|3U|K|L]|$I|3V|J|3W|K|L]|$I|3X|J|3Y|K|L]]|9|@]|A|$]]|$1|12|3|13|5|D|7|3Z|8|@]|9|@]|A|$E|F]]|$1|14|3|15|5|6|7|40|8|@$I|41|J|42|K|L]|$I|43|J|44|K|L]|$I|45|J|46|K|L]|$I|47|J|48|K|L]]|9|@]|A|$]]|$1|16|3|17|5|6|7|49|8|@]|9|@$I|4A|J|4B|1|4C]]|A|$]]|$1|18|3|19|5|D|7|4D|8|@]|9|@]|A|$E|F]]|$1|1A|3|1B|5|6|7|4E|8|@$I|4F|J|4G|K|L]|$I|4H|J|4I|K|L]|$I|4J|J|4K|K|L]|$I|4L|J|4M|K|L]|$I|4N|J|4O|K|L]|$I|4P|J|4Q|K|L]|$I|4R|J|4S|K|1C]]|9|@]|A|$]]|$1|1D|3|1E|5|D|7|4T|8|@]|9|@]|A|$E|F]]|$1|1F|3|1G|5|6|7|4U|8|@]|9|@]|A|$]]|$1|1H|3|1I|5|6|7|4V|8|@$I|4W|J|4X|K|L]|$I|4Y|J|4Z|K|L]]|9|@$I|50|J|51|1|52]]|A|$]]|$1|1J|3|1K|5|D|7|53|8|@]|9|@]|A|$E|F]]|$1|1L|3|1M|5|6|7|54|8|@$I|55|J|56|K|L]|$I|57|J|58|K|L]|$I|59|J|5A|K|L]]|9|@]|A|$]]|$1|1N|3|1O|5|6|7|5B|8|@$I|5C|J|5D|K|L]|$I|5E|J|5F|K|L]|$I|5G|J|5H|K|L]|$I|5I|J|5J|K|L]|$I|5K|J|5L|K|L]]|9|@]|A|$]]|$1|1P|3|1Q|5|6|7|5M|8|@]|9|@]|A|$]]|$1|1R|3|1S|5|6|7|5N|8|@]|9|@$I|5O|J|5P|1|5Q]]|A|$]]|$1|1T|3|-4|5|6|7|5R|8|@]|9|@]|A|$]]]|1U|$1V|$5|1W|1X|1Y|A|$1Z|20]]|21|$5|1W|1X|1Y|A|$1Z|22]]|23|$5|1W|1X|1Y|A|$1Z|24]]|25|$5|1W|1X|1Y|A|$1Z|26]]|27|$5|1W|1X|1Y|A|$1Z|28]]|29|$5|1W|1X|1Y|A|$1Z|2A]]|2B|$5|1W|1X|1Y|A|$1Z|2C]]|2D|$5|1W|1X|1Y|A|$1Z|2E]]]]

TL;DR: you need to swap your two call signatures like this:
<pre><code>function doStuff(arg: Map&lt;any, any&gt;): Map&lt;any, any&gt;;
function doStuff(arg: Record&lt;any, any&gt;): Record&lt;any, any&gt;;
function doStuff(arg: any) {
 return arg;
}
</code></pre>
<hr />
The type <code>Record&lt;any, any&gt;</code> (using <a href="https://www.typescriptlang.org/docs/handbook/utility-types.html#recordkeystype" rel="nofollow noreferrer">the <code>Record&lt;K, V&gt;</code> utility type</a>) is equivalent to <code>{[x: string]: any}</code>:
<pre><code>type RecordAnyAny = Record&lt;any, any&gt;;
// type RecordAnyAny = {[x: string]: any}
</code></pre>
an object-like type with a <code>string</code> <a href="https://www.typescriptlang.org/docs/handbook/2/objects.html#index-signatures" rel="nofollow noreferrer">index signature</a> whose properties are of <a href="https://www.typescriptlang.org/docs/handbook/2/everyday-types.html#any" rel="nofollow noreferrer">the <code>any</code> type</a>. So it can have any keys at all, and any values at all. So just about any object will be assignable to it:
<pre><code>let r: RecordAnyAny
r = {}; // okay
r = {a: 0, b: &quot;one&quot;, c: true}; // okay
r = new Date(); // okay;
r = new Map(); // okay, note well
</code></pre>
As you can see, even <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Map" rel="nofollow noreferrer">a <code>Map</code> object</a> is assignable to <code>Record&lt;any, any&gt;</code>.
<hr />
On the other hand, the <code>Map&lt;K, V&gt;</code> type is <a href="https://github.com/microsoft/TypeScript/blob/6834969f8f20d0cf64a40cc8d146a1be3d5440b0/lib/lib.es2015.collection.d.ts#L21-L29" rel="nofollow noreferrer">an <code>interface</code> defined in the TypeScript library</a> as something like:
<pre><code>interface Map&lt;K, V&gt; {
 clear(): void;
 delete(key: K): boolean;
 forEach(callbackfn: (value: V, key: K, map: Map&lt;K, V&gt;) =&gt; void, thisArg?: any): void;
 get(key: K): V | undefined;
 has(key: K): boolean;
 set(key: K, value: V): this;
 readonly size: number;
}
</code></pre>
And <code>Map&lt;any, any&gt;</code> is equivalent to the above interface with <code>any</code> substituted in for both <code>K</code> and <code>V</code>.
This type is more restrictive than <code>Record&lt;any, any&gt;</code>. If I have a value <code>m</code> of type <code>Map&lt;any, any&gt;</code>, I know that it will have, say, a <code>get()</code> method, but with <code>Record&lt;any, any&gt;</code>, I don't know that, so it's not safe to use a <code>Record&lt;any, any&gt;</code> as a <code>Map&lt;any, any&gt;</code> (while it is safe to do the reverse):
<pre><code>let m: Map&lt;any, any&gt; = new Map();
m = r; // error
// Type 'RecordAnyAny' is missing the following properties from
// type 'Map&lt;any, any&gt;': clear, delete, forEach, get, and 8 more.(2740)
</code></pre>
So, hopefully this is clear: every <code>Map&lt;any, any&gt;</code> is a <code>Record&lt;any, any&gt;</code>, but not every <code>Record&lt;any, any&gt;</code> is a <code>Map&lt;any, any&gt;</code>.
<hr />
Now we can look at your <a href="https://www.typescriptlang.org/docs/handbook/2/functions.html#function-overloads" rel="nofollow noreferrer">overloaded function</a>:
<pre><code>// call signatures 
function doStuffOld(arg: Record&lt;any, any&gt;): Record&lt;any, any&gt;;
function doStuffOld(arg: Map&lt;any, any&gt;): Map&lt;any, any&gt;;

// implementation
function doStuffOld(arg: any) {
 return arg;
}

doStuffOld(new Map&lt;any, any&gt;());
</code></pre>
When you call an overloaded function, the compiler picks the first matching call signature. So for <code>doStuffOld(new Map&lt;any, any&gt;())</code>, the compiler examines the first call signature <code>(arg: Record&lt;any, any&gt;) =&gt; Record&lt;any, any&gt;</code>. Does it work? YES. Every <code>May&lt;any, any&gt;</code> is also a <code>Record&lt;any, any&gt;</code>, so the compiler selects this overload. And so the return type is also <code>Record&lt;any, any&gt;</code>, and it's an error to assign the result to a <code>Map&lt;any, any&gt;</code>:
<pre><code>m = doStuffOld(new Map&lt;any, any&gt;()); // error!
</code></pre>
The second call signature is never reached. Oops.
<hr />
Because <code>Map&lt;any, any&gt;</code> is more specific than <code>Record&lt;any, any&gt;</code>, you need to swap the order of your two call signatures. This advice is also given in <a href="https://www.typescriptlang.org/docs/handbook/declaration-files/do-s-and-don-ts.html#ordering" rel="nofollow noreferrer">the TypeScript Handbook's Do's and Don'ts for function overloads</a>:
<pre><code>// call signatures
function doStuff(arg: Map&lt;any, any&gt;): Map&lt;any, any&gt;;
function doStuff(arg: Record&lt;any, any&gt;): Record&lt;any, any&gt;;

// implementation
function doStuff(arg: any) {
 return arg;
}

m = doStuff(new Map&lt;any, any&gt;()); // okay
r = doStuff({a: 0, b: &quot;one&quot;, c: true}); // okay
</code></pre>
Now when you call <code>doStuff(new Map&lt;any, any&gt;())</code>, the compiler tries the <code>Map</code> call signature first. That matches, so you get the <code>Map</code> return type.
And when you call <code>doStuff({a: 0, b: &quot;one&quot;, c: true})</code>, the compiler tries the <code>Map</code> call signature but it does not match (since that object is not a <code>Map</code>), so it then tries the <code>Record</code> call signature which does match... and you get the <code>Record</code> return type.
So now everything should work as desired.
<a href="https://www.typescriptlang.org/play?ts=4.6.2#code/C4TwDgpgBAShDGB7ATgEwIIDsRZFAvLAiqgDwCG2ANFJSAHwDcAUAPStSiRFJq64EoAbwDaADwBcUAM7BkAS0wBzALpS6AX2bMANhGBRkUuLwzZczZIKEbGUdlEQBrciEvXyUgAw0ARlIAiREwIAJp4KTkAVwhbew5nV3dCEIB3KAARcmAIAAoASjsHRJAWKxSIdIBZcjACooSXN119KABbKRqwCmpabHpBNKgu+uY2wWQGqAhkZBQ2DgAVcGgAchMSfmxVqHlpdr3pRSVOAAtoADNEHR1EVOOoMDnIZGB5CH2LubaFqE4VqCrLo9EA0Oj0VZSeB6cjIGioCB6HI0K7IACi5HgpxoSn0YMwqCgAA52igIAA6XIAJgA7AAWLz5bS-eDkG4yeRKTDZKLID5QZgXKKYeBvYJQVCIADKwCiFwuAHkdKhcrClMZiGgQfiGPkNaZtX0GCwhSKxZgJdLZfKlSq1Z1aobwXrho66DqmL95G0wHo2hBMMBsvJgoLhaKQxbJTK5YrlarkOqjflhMw-nzZcgLWqWFoxoJo9a4yqhsD3Ub6AVCvFprMUABCZmmiPiwuxhNJsu9Z0O7rl8Em8Pmy0x+Ud-UkJ39F0bLX9-qDs2RkdF8fJ1Pp-S87OJ3PacaENtj0tu7v9KtTErJFftoSeKA+KD+KBBEJhKARTjIGIaavFJrMkAA" rel="nofollow noreferrer">Playground link to code</a>

This is a pretty simple use case.
I have an overloaded signature which sometime accepts a Record, sometime a Map. Although I am using the Map version, somehow TS thinks I'm using the Record one. Why ? How should I fix this ?
<pre class="lang-js prettyprint-override"><code>
function doStuff(arg: Record&lt;any, any&gt;): Record&lt;any, any&gt;;
function doStuff(arg: Map&lt;any, any&gt;): Map&lt;any, any&gt;;
function doStuff(arg: any) {
 return arg;
}
 
let m: Map&lt;any, any&gt; = doStuff(new Map&lt;any, any&gt;());
// error ! m is returned as a Record
</code></pre>
also see <a href="https://www.typescriptlang.org/play?ssl=9&amp;ssc=1&amp;pln=1&amp;pc=1#code/GYVwdgxgLglg9mABAEzgZSiYwAUBDAJwHMAuRAJQFMI4DkAePMATwBpEnmA%20ASjKpp1GLdpy4BuAFChIsBCnSZs%20YmQCyeAA7C2HFr3Vado-VOnho8JKgxZchUnuY9EAb0mJEBSpgJIHUgC%20kpIANj6IALaG2pwm3IgAvAq2ymCUAO6IGrEiTlw4PDxSQA" rel="nofollow noreferrer">the playground</a>

Signature overload does not work as expected: Record vs Map

翻译质量差，导致语言生硬或混乱。

没有提供实际的解决方法或示例。

解答不清晰，无法理解或解决问题。

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这是一个非常简单的用例。我有一个过载的签名，有时接受记录，有时接受Map。尽管我使用的是Map版本，但TS认为我使用的是记录版本。为什么？我该怎么解决这个问题？function doStuff(arg: Record<any, any>): Record<any, any>;function doStuff(arg: ...

问签名重载不像预期的那样工作:记录vs Map
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问签名重载不像预期的那样工作:记录vs Map
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