Should you use constexpr?

Should you use constexpr?

The primary usage of constexpr is to declare intent. If an entity isn’t marked as constexpr – it was never intended to be used in a constant-expression; and even if it is, we rely on the compiler to diagnose such context (because it disregards our intent).

Is constexpr faster?

With the release of C++14, the standards committee strengthened one of the coolest modern features of C++: constexpr . Now, C++ developers can write constant expressions and force their evaluation at compile-time, rather than at every invocation by users.

What is constexpr in C?

The constexpr keyword, short for constant expression, was a feature introduced in C++11 that allows the value of an expression to be evaluated at compile-time.

What is a constexpr function?

A constexpr function is a function that can be invoked within a constant expression. A constexpr function must satisfy the following conditions: It is not virtual. Its return type is a literal type. Each of its parameters must be of a literal type.

Is constexpr inline?

The constexpr keyword implies inline. Performing computations at compiletime can have many advantages over doing them at runtime. Firstly it can increase runtime performance, as computations that would be done at runtime are already executed at compiletime.

Is constexpr always static?

3 Answers. The short answer is that not only is static useful, it is pretty well always going to be desired. First, note that static and constexpr are completely independent of each other. static defines the object’s lifetime during execution; constexpr specifies that the object should be available during compilation.

Is constexpr a const?

constexpr variables A constexpr variable must be initialized at compile time. All constexpr variables are const . A variable can be declared with constexpr , when it has a literal type and is initialized.

Is constexpr variable inline?

Also, note that constexpr variables are inline implicitly, so there’s no need to use constexpr inline myVar = 10; .

Is constexpr always const?

(This is possible when the address is generated by applying the address operator to a static/global constant expression.) Here, both constexpr and const are required: constexpr always refers to the expression being declared (here NP ), while const refers to int (it declares a pointer-to-const).