Tag Archives: correctness

Toggles in functions

Have you ever seen a function call like this? We are processing something: this should be clear from the context. But what do these parameters mean? What is true and what is false? From the function call we will never … Continue reading

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(Not) detecting bugs

The following code contains a bug. A developer has spent quite some time looking for the source. The intent of this code is to iterate over two vectors simultaneously, from the first up to the one-before-last element. Thus the most … Continue reading

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More const — fewer bugs

I have just read article “Please declare your variables as const” by Bartłomiej Filipek. It argues that declaring your variables const is beneficial for reasons other than performance. In particular, it can help find bugs in your code. Now, let … Continue reading

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Concealing bugs

Consider the following piece of program code. This program is expected to open file contents.txt, read names from it; then find a desired name, and do something with it. But the program will not do it, because I have a … Continue reading

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The One-Definition Rule

We have been hit by the same bug twice already this year. It ends in a crash, and it took developers days to find it (in each case), even though it is reproducible on each run of unit tests. The … Continue reading

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Competing constructors

We start with a known C++ gotcha: In this post I want to analyze the source of the problem a bit further, and offer some suggestions on class design.

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Concepts without Concepts

“Concept” can mean two things in the context of C++ generic libraries: Something informal: something we know about template parameters, and can tell to other human programmers, e.g. in documentation. A language feature. This post is about concepts in the … Continue reading

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