Add support for @template JSDoc

[NoelAbrahams]

Hi, it will be useful to be able to document generic parameters:

/** The foo class.
  * @template TFirst ...
  * @template TSecond ... */
class Foo<TFirst, TSecond> {

}

var foo = new Foo< // Info

[johnnyreilly]

+1 for this

[danquirk]

This tag appears to be undocumented but supported in WebStorm for this same purpose so may be reasonable to go ahead with it (http://stackoverflow.com/questions/16017627/document-generic-type-parameters-in-jsdoc).

[kitsonk]

Carried over from #5854, it was pointed out that Closure Compiler documents this feature.

[Liero]

I'm not sure what is the final syntax for documenting generic arguments. Can you point to documentation or briefly describe, please?

[billti]

@Liero see the examples at https://github.com/Microsoft/TypeScript/wiki/JsDoc-support-in-JavaScript

[unional]

@RyanCavanaugh is it in nightly? I check and 2.1.0-dev.20160712 does not work:

The "@template T Inferred ...." is treated as part of summary.

[mhegazy]

@unional can you log a new issue with more details

[unional]

Done. 🌷

[zpdDG4gta8XKpMCd]

please update https://github.com/Microsoft/TypeScript/wiki/JSDoc-support-in-JavaScript

[art-in]

so narrowing generic type @template T is supported?
the case was mentioned in #5854, but I cannot find any example.

same question: https://stackoverflow.com/questions/44080759/is-it-possible-to-constrain-a-generic-type-defined-in-a-jsdoc-template-declarat

[villelahdenvuo]

I just came to ask the same question, but it seems like the answer is no.

[mhegazy]

Looking at the closure documentation for @template (https://github.com/google/closure-compiler/wiki/Generic-Types), does not seem that the standard has any support for this. One option is to make a new syntax, @template T {Object} to define a constraint. I would file a new suggestion for that.