The impact of constexpr on algorithms and containers

With the introduction of the constexpr specifier in C++11 and its enhancements in subsequent versions, compile-time computation in C++ has taken a significant leap. The ability for functions and constructors to operate at compile time via constexpr enables optimization and assurance of specific attributes before the code runs. This section examines the integration of constexpr within the STL, particularly concerning algorithms and containers.

Evolution of constexpr

In its infancy during C++11, constexpr was primarily for straightforward computations. The C++14 extension broadened its scope, embracing loops and conditional structures. By C++20, there was further augmentation allowing for constexpr allocations via std::allocator. This made containers such as std::vector and std::string usable with constexpr, though with certain restrictions.

Algorithms and the role of constexpr

Originally, constexpr wasn’t widely...