Tag Archives: concepts

Concepts — case studies

This post has been inspired by the readers’ questions about using concepts to solve real problems. We will have a look at two such problems and see if, and how, concepts can help. Case Study 1 My concept has two … Continue reading

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Decent concepts

Last year I published two posts on writing concepts: Concept Archetypes, Semantic requirements in concepts. Having had some time to reflect upon these posts, I now realize that the model presented in them is not complete. In this post I … Continue reading

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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

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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.

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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

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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


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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

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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

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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

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