Why Use `std::begin` and `std::end` Over Member Functions in C 11?

Deciphering the Benefits of Non-Member begin and end Functions in C 11

In C 11, the existence of non-member begin and end functions has raised questions about their significance and benefits. While they essentially mirror the member functions within standard containers, there are underlying advantages to consider.

The Question:

Why utilize the free functions std::begin and std::end instead of their member counterparts for iterators in container handling?

The Answer:

1. Generic Programming Extension:

Non-member functions provide flexibility in generic programming. When working with data structures that cannot be modified (e.g., C arrays), the free functions offer a solution. For instance, std::begin(array) and std::end(array) can be employed to retrieve iterators for such data structures, allowing uniform treatment within generic algorithms.

Consider the example of sorting an array using std::sort:

<code class="cpp">int arr[] = {1, 3, 2, 5, 4};

std::sort(std::begin(arr), std::end(arr));</code>

In this scenario, std::begin and std::end enable the seamless sorting of a C array without requiring member function availability.

2. Handling Structures with Ambiguous Member Functions:

Another advantage emerges when dealing with structures that potentially define member functions called begin and end. In such cases, ambiguity arises because both the member and non-member versions are available to the compiler. By explicitly specifying std::begin and std::end, this ambiguity can be resolved, ensuring the intended functionality.

Conclusion:

While free functions may not introduce significant character savings for standard containers, they offer substantial benefits for generic programming and handling non-standard containers or structures with ambiguous member functions. Their adoption aligns with C 11's emphasis on extensibility, flexibility, and improved code clarity.

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