Auto-detect C++ type on extensionless headers based on the first line

Type: LanguageService

Auto-detect C++ type on extensionless headers based on the first line

• OS and Version: Any
• VS Code Version: 1.38.1
• C/C++ Extension Version: Version 0.25.1

To Reproduce

1. Open up any file lacking an extension
2. Observe how it is not syntax colored without human intervention

Expected behavior

Standard C++ library and some open source libraries use extensionless headers.
Other editors (including viewer of github) are able to recognize that by scanning the first line of the header that embeds a - C++ - string in the comment.

Example: https://github.com/llvm-mirror/libcxx/blob/master/include/vector

Here are other examples of the first line of the extensionless files from several popular open source projects:

// -*- C++ -*-

or

//===- some description ---*- C++ -*-==//

Related issue on vscode

https://github.com/Microsoft/vscode/issues/23873

Non sono indicati file di implementazione né test. Inizia riproducendo il comportamento con un header senza estensione, quindi esamina l’issue correlata di VS Code e la gestione dei tipi di file da parte del servizio linguistico dell’estensione C/C++. Il lavoro è completato quando vengono riconosciuti i marker C++ mostrati nella prima riga e viene applicata la colorazione della sintassi C++ senza intervento manuale.