Some common cases where the evaluation order has so far been unspecified, are specified and valid with C++17. Some undefined behaviour is now instead unspecified. i = 1; f(i++, i) was undefined, but it is now unspecified. Specifically, what is not specified is the order in which each argument to f is evaluated relative to … Read more
Copy elision was permitted to happen under a number of circumstances. However, even if it was permitted, the code still had to be able to work as if the copy were not elided. Namely, there had to be an accessible copy and/or move constructor. Guaranteed copy elision redefines a number of C++ concepts, such that … Read more
How to read: This article is rather long. If you want to know about both aggregates and PODs (Plain Old Data) take time and read it. If you are interested just in aggregates, read only the first part. If you are interested only in PODs then you must first read the definition, implications, and examples … Read more
Strictly speaking, the behavior is undefined: 6.5 Expressions … 2 If a side effect on a scalar object is unsequenced relative to either a different side effect on the same scalar object or a value computation using the value of the same scalar object, the behavior is undefined. If there are multiple allowable orderings of the … Read more