Use the New Span Class to Make Our C-Arrays Safer
Explore how the C++20 stdspan class offers a safer way to handle C-arrays by creating a lightweight, non-owning view over contiguous data. Discover how spans enable passing arrays to functions with size information, improving code clarity and safety while maintaining minimal overhead.
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New for C++20, the std::span class is a simple wrapper that creates a view over a contiguous sequence of objects. The span doesn't own any of its own data, it refers to the data in the underlying structure. Think of it as string_view for C-arrays. The underlying structure may be a C-array, a vector, or an STL array.
How to do it
We can create a span from any compatible contiguous-storage structure. The most common use case will involve a C-array. For example, if we try to pass a C-array directly to a function, the array is demoted to a pointer and the function has no easy way to know the size of the array:
void parray(int * a); // loses size information
If we define our function with a span ...