In addition to what others have said, I'd like to plug the actual documentation for the Copy trait, which was very helpful for me in grasping what it means/does:
And also this post by @trentj in an old thread:
By "original value" I mean a, not b.
a = b; always does the same thing for all types, Copy or not. It copies the bits just like in C.
Again, a = b; is equally expensive whether or not the type is Copy. There may be a second order effect where making a type Copy allows the programmer to do things that inhibit the compiler's ability to optimize away that cost, but implementing Copy itself has no effect on code generation at all.
I actually believe that @yushang 's observation that there is a …
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