Failed to highlight C++ code

[fengwang]

inserting cpp source code such like

int function( double x )
{
    return std::floor( x );
}

but unfortunately the output code is not highlighted.

[ele828]

Hi, it works well on my local machine. Did you add cpp annotation to your markdown?

```cpp    // Like this one
int function( double x )
{
    return std::floor( x );
}
\```

FYI, you can find supported language shorthand here: http://prismjs.com/#languages-list

If it's still not resolved, feel free to reopen this issue.

[fengwang]

@ele828 Thank you very much for your kind reply. I have tried both

    ```language-cpp
    //my code
    ````

and

    ```cpp
    //my code
    ````

but no luck.

In the _config.xml file, I have already set

highlight:
  enable: false
  line_number: false
  auto_detect: false
  tab_replace:

and

prism_plugin:
    mode: 'realtime'
    theme: 'coy'
    line_number: true

One of the generated page demonstrating this problem is available at this blog