C/C++ Rarer keywords - register, volatile, extern, explicit
Can you give me a quick runthrough of what these 4 keywords are used for and why?

I understand the basics that google would tell you on register and volatile, but would like to know a little more (just a practical overview).  Extern and explicit confuse me a little as I've never found a reason to have to use them myself despite doing fairly low-level embedded systems code.  Again, I can google but I'd prefer a quick, practical summary from an expert so it sticks in my mind.

Thanks!

-w00te
C/C++ Rarer keywords - register, volatile, extern, explicit
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Can you give me a quick runthrough of what these 4 keywords are used for and why?

I understand the basics that google would tell you on register and volatile, but would like to know a little more (just a practical overview).  Extern and explicit confuse me a little as I've never found a reason to have to use them myself despite doing fairly low-level embedded systems code.  Again, I can google but I'd prefer a quick, practical summary from an expert so it sticks in my mind.

Thanks!

-w00te