Using Concepts to Constrain Auto Parameters
Explore how to constrain auto parameters using concepts in C++20 to improve code safety and readability. Understand abbreviated function templates, specialization, and constrained auto for functions and lambdas. This lesson helps you apply these constraints to write clearer, more reliable C++ template code.
We'll cover the following...
In the “Template Fundamentals” section, we discussed generic lambdas, introduced in C++14, as well as lambda templates, introduced in C++20. A lambda that uses the auto specifier for at least one parameter is called a generic lambda. The function object generated by the compiler will have a templated call operator. Here’s an example to refresh our memory:
auto lsum = [](auto a, auto b) {return a + b; };
Abbreviated function templates
The C++20 standard generalizes this feature for all functions. We can use the auto specifier in the function parameter list. This has the effect of transforming the function into a template function. Here’s an ...