I'm guessing the author measured the overall performance and assumed that using error codes, rather than exceptions, is what made the sample code he provided slower. Turns out, the reason it is slower is because, in the case using error codes, a copy of a std::string is made. In the exceptions case, where the string is returned rather than passed as a parameter by reference, the copy can be elided because the compiler invokes NVRO. Has nothing to do with exceptions.
Maybe that author should use a profiler before making these types of claims? check the generated assembly? etc?
Far slower to return a value in RAX vs. generate a ton of code (blowing icache, etc.) is quite an interesting statement. I think it deserves a closer look, though.
Maybe that author should use a profiler before making these types of claims? check the generated assembly? etc?
Far slower to return a value in RAX vs. generate a ton of code (blowing icache, etc.) is quite an interesting statement. I think it deserves a closer look, though.