What does this do?

This will get you the bleeding-edge syntax highlighting for C, C++, Objective-C, and Objective-C++. Which means your theme will be able to color your code better. This used to be a fix, but then VS Code starting using it as the official source for C and C++ highlighting.

NOTE: The default VS Code theme does not color much. Switch to the Dark+ theme (installed by default) or use a theme like one of the following to benefit from the changes:

How do I use it?

Just install the VS Code extension and the changes will automatically be applied to all relevent files.
Link: https://marketplace.visualstudio.com/items?itemName=jeff-hykin.better-cpp-syntax

Before and After (Material Theme)

Before	After

What is different from atom/language-c?

It fixes:

The issue of single quotes inside #error and #warning being highlighted when then shouldn't be
The issue of initilization functions only highlighting the first paraenthese
The bug that treats the 'and' and 'or' operator as functions (instead of operators) when they are followed by ()'s
Old C99 function highlighting that broke the standard function highlighting
The failure of highlighting for the semicolon after namespaces
The missing operator overloading symbols
The failure to tag operator overloading functions as functions
The failure to tag implicit operator overrides
The marking of some %'s as invalid inside of strings https://github.com/atom/language-c/issues/289
The highlighting of namespaces with ::'s https://github.com/atom/language-c/issues/260
The issue of the C++ syntax depending on (and getting screwed up by) the C syntax
multiple inheritance https://github.com/atom/language-c/issues/245
And many many more issues (#318, #309, #270, #246, etc)

It adds:

Parameter highlighting
Highlighting of embedded assembly code (if you have an assembly syntax installed)
Function-pointer highlighting
Lambda highlighting
C++14 literal support (100'000ms)
Template definition syntax highlighting (including C++ 2020 syntax)
Better object identification
Improved scope resolution :: syntax
Highlighting of templated function calls aFunction<int>(arguments)
Additional specificity for many existing tags
Many other features

Contributing

If you'd like to help improve the syntax, take a look at source/languages and look at the generate.rb files. And make sure to take a look at CONTRIBUTING.md to get a better idea of how code works.

Planned future fixes/featues:

Add tagging for type-casting statements
Add tagging for template-usage (rather than only template definition)
Add tagging for custom types words
Better support for dereferenced/pointer tagging

What if I see a highlighting bug?

Let me know! Post an issue on https://github.com/jeff-hykin/cpp-textmate-grammar I love regular expressions, and I plan on actively maintaining this.

Did you write all of this youself?

The original JSON was taken from https://github.com/atom/language-c
The #error fix was taken from fnadeau's pull request here: https://github.com/atom/language-c/pull/251
@matter123 has written basically every pull request, from simple bugfixes up to the entire textmate testing suite
Thanks @matter123!
The rest of the ruby is authored by @jeff-hykin

Better C++ Syntax

Jeff Hykin