//*/ to terminate block comments, then use
//* to toggle the block in and out of code.
So this is a small trick but it’s really useful — a syntax hack at the same kind of level of a keyboard shortcut.
Most C-syntax langauges use line comments and block comments like so;
// line comment /* block comment */
Block comments mask more code, but they tend to be ‘fiddly’ to put into your code and take out. This can be a pain when you have a block you’re developing and you want to comment it in and out regularly;
/* ... big code block here ... which goes on for a while ... and you want to toggle it ... in and out regularly. */
So if you change your terminating symbol to
//*/, an interesting thing happens; it functions as the terminator of a block comment inside a block comment, but a line comment otherwise. This means you can toggle code in and out by putting a single extra slash on the start of the block comment;
/* code here commented out //*/
//* code here is now active //*/
So there is it. A single-character togle of a block comment.