Noexcept in C : When Does This Keyword Actually Boost Performance?

Noexcept: Beyond Theoretical Considerations

Despite its potential, the noexcept keyword raises practical questions for developers. Let's explore when its application is truly beneficial and how it impacts program efficiency.

1. Consistent Usage of noexcept for Unthrowable Functions:

Should all functions known to never throw require a noexcept annotation explicitly? The answer is situation-specific. For functions where the compiler cannot naturally deduce non-throwing behavior, adding noexcept can be beneficial. However, blindly appending noexcept to every function would indeed be counterproductive.

2. Performance Enhancements with noexcept:

The primary motivation for using noexcept is the potential optimization it enables for the compiler. However, it's important to note that not all compilers currently take full advantage of this feature. The most significant performance gains are typically realized when noexcept is applied to the "big four" operations of constructors, assignment operators, and move operations. By explicitly marking these functions as non-throwing, the compiler can avoid unnecessary exception handling code, potentially reducing binary size and improving performance.

Conclusion:

While noexcept offers the promise of improved optimization, its practical value is still evolving. For functions where non-throwing behavior is not evident to the compiler, adding noexcept can be beneficial. However, it's crucial to balance this with programmer productivity. Ultimately, the decision of when to use noexcept should be made on a case-by-case basis, considering the compiler's capabilities and the potential performance impact.

The above is the detailed content of Noexcept in C : When Does This Keyword Actually Boost Performance?. For more information, please follow other related articles on the PHP Chinese website!