Why Use `= default` for Default Constructors in C 11?

Why Use "= default" in C 11 Default Constructors?

The traditional default constructor syntax in C involved simply defining an empty constructor function:

However, C 11 introduced the "= default" syntax, which provides several benefits:

1. Explicit Delineation of ODR-Use: An explicitly defaulted default constructor is specifically defined by the standard as identical to a user-defined default constructor with no initialization list and an empty compound statement. This ensures consistent behavior across different use cases.
2. Aggregate and Trivial Type Properties: While a traditional empty constructor retains aggregate and trivial type properties, a declared default constructor, even an empty one, does not. Using "= default" explicitly removes these properties if desired.

1. Matching Properties of Implicit Constructor: The "= default" syntax ensures that the explicitly defined default constructor matches the properties of the implicit constructor, including constexpr and exception specifications. This improves code readability.
2. Uniform Syntax: The "= default" syntax provides a uniform method for defining special member functions like copy/move constructors and destructors, making code more consistent and easier to understand.

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