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Warning on ignored return?
» Home : Blog : April 2004
A few months back, I wrote about wanting a warning from C++, and not being able to get one. It happened again.
We have code like this:
If you read the comments and signature of the Trim() method, you see that it returns a copy of the string. But if you are less careful, you can think that this method trims the string in place:
CMyString fooey(" this needs trimming. ");
I figured, there ought to be a way to get a compiler warning: not only is the return value ignored, but the method is declared const, so it conceptually has no side effects. I know: the const aspect can be worked around, but still, why can't the compiler warn me about this?
There's a warning that can tell me that I've used an enumeration type in a switch, and have not provided a case for every enumeration value. This warning will appear even if there is a default clause! If this is something that can be warned about, why not ignoring the return from a const method?
tagged: c++» 2 reactions