Tag Archives: C++20
Semantic requirements in concepts
The word ‘concept’ in the context of C++ generic programming has two meanings. The first is more abstract: it is the notion from the domain of Generic Programming (GP) in general. GP is not tied to any specific language: it … Continue reading
Concept archetypes — update
An observant reader indicated that in the previous post where I was trying to implement a concept archetype — a type with minimal interface that models a given concept — I actually failed. This deserves a closer examination.
Concept archetypes
Concepts in the form added in C++20 used to be called lite. This is because they do not provide one quite important functionality: having the compiler check if the author of a constrained template is only using operations and types … Continue reading
Ordering by constraints
In the previous post we have seen how constraint conjunction and disjunction works, and how a function template with constraints is a better match than a function template without constraints (provided that the constraints are satisfied) when determining the best … Continue reading
Requires-clause — updated
The previous post, “Requires-clause”, contained incorrect information about parentheses inside a requires-clause. Token || inside parentheses is still interpretted as a disjunction of two constraints. I apologize for misleading the readers. I also want to thank James Pfeffer for bringing … Continue reading
Requires-clause
Update. This post in its original form contained incorrect information about the meaning of parentheses inside requires-clauses in section Conjunction and Disjunction. The section has now been changed to correct this. The updated text is in blueish color. Even if … Continue reading
Requires-expression
This post is about a C++20 feature, so we will be talking about the future. However, this is a very near feature, C++20 is expected to go out this year, and concepts look really stable, so the chances are high … Continue reading
String literals make bad ranges
C++20 will come with what we call “Ranges” library. Meanwhile, range interface has been supported ever since C++11 in one context: range-based for loop. A range-based for loop can detect anything that is a range and work with it. In … Continue reading