Use a Unicode surrogate pair character in Arduino IDE
There is a nifty new feature in C++11 called string literal, this example shows how to use it with any single line or multi line or utf8 text. You just define starting and ending sequence, in following case --- (starting sequence becomes R"---( and ending sequence )---") and make sure that this sequence does not appear in encapsulated text. This is great for integrating websites into arduino projects:

static const char _index_html[] PROGMEM = R"---(
&lt;html&gt;
&lt;head&gt;
&lt;link rel="icon" type="image/png" href="/favicon.png"/&gt;
&lt;/head&gt;
&lt;body&gt;
...
&lt;/body&gt;
&lt;/html&gt;
)---";